Stanley–Wilf limit for the permutation pattern ()
Stanley–Wilf limit for the permutation pattern : determine or improve its bounds; the repository records 10.27 (lower) and 13.5 (upper).
Editorial MSC2020 classification. Original article codes and source evidence are recorded in the literature directory.
Problem statement
Let be the set of permutations of that avoid the permutation pattern , and let
The Stanley–Wilf limit (growth constant) for the pattern is
Equivalently, , the growth rate of the permutation class avoiding .
This limit is known to exist (and to be finite) for every fixed pattern, as a consequence of Marcus–Tardos and Arratia.
Lean 4
No Lean statement or proof is attached yet. Have a formalization? Share its source to add it to this problem.
Background
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Determining the exact value of remains open. [BBEPP2017-open]
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The best current rigorous bounds are . [BBEPP2017-t1-thiswork]
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Claesson, Jelínek and Steingrímsson conjectured a statement about -avoiding permutations with a fixed number of inversions, which (if true) would imply the improved upper bound
see [CJS12] (and [BBEPP2017] for a brief summary). [CJS12-cond-ub] [BBEPP2017-cond-ub]
- Conway, Guttmann and Zinn-Justin have analysed the series for the number of -avoiding permutations in and give a numerical estimate for of . They also conjecture that behaves asymptotically as
for certain estimated constants ; see [BBEPP2017] for a summary. [BBEPP2017-estimate] [BBEPP2017-asymptotic]
References (from the repository page)
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[BBEPP2017] Bevan, David; Brignall, Robert; Elvey Price, Andrew; Pantone, Jay. A structural characterisation of Av(1324) and new bounds on its growth rate. Preprint (2017), last revised 2019. Google Scholar. arXiv PDF. Publisher entry
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[BBEPP2017-open] loc: arXiv v3 PDF p.1, Section 1 (Introduction). quote: “In contrast, even the exponential growth rate of remains to be determined exactly.”
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[BBEPP2017-def-gr] loc: arXiv v3 PDF p.2, Section 1 (Introduction). quote: “The exponential growth rate of the class is , where denotes the set of permutations of length that avoid . This limit is known to exist as a consequence of the resolution of the Stanley-Wilf conjecture by Marcus and Tardos [26].”
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[BBEPP2017-t1-ub-288] loc: arXiv v3 PDF p.2, Section 1 (Introduction), Table 1. quote: “Lower Upper 2004: Bóna [5] Table 1: A chronology of lower and upper bounds for ”
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[BBEPP2017-t1-lb-9] loc: arXiv v3 PDF p.2, Section 1 (Introduction), Table 1. quote: “Lower Upper 2005: Bóna [6] Table 1: A chronology of lower and upper bounds for ”
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[BBEPP2017-t1-lb-9.47] loc: arXiv v3 PDF p.2, Section 1 (Introduction), Table 1. quote: “Lower Upper 2006: Albert et al. [1] Table 1: A chronology of lower and upper bounds for ”
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[BBEPP2017-t1-ub-16] loc: arXiv v3 PDF p.2, Section 1 (Introduction), Table 1. quote: “Lower Upper 2012: Claesson, Jelínek and Steingrímsson [13] Table 1: A chronology of lower and upper bounds for ”
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[BBEPP2017-t1-ub-13.93] loc: arXiv v3 PDF p.2, Section 1 (Introduction), Table 1. quote: “Lower Upper 2014: Bóna [8] Table 1: A chronology of lower and upper bounds for ”
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[BBEPP2017-t1-lb-9.81] loc: arXiv v3 PDF p.2, Section 1 (Introduction), Table 1. quote: “Lower Upper 2015: Bevan [3] Table 1: A chronology of lower and upper bounds for ”
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[BBEPP2017-t1-ub-13.74] loc: arXiv v3 PDF p.2, Section 1 (Introduction), Table 1. quote: “Lower Upper 2015: Bóna [9] Table 1: A chronology of lower and upper bounds for ”
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[BBEPP2017-t1-thiswork] loc: arXiv v3 PDF p.2, Section 1 (Introduction), Table 1. quote: “Lower Upper This work Table 1: A chronology of lower and upper bounds for ”
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[BBEPP2017-cond-ub] loc: arXiv v3 PDF p.2, Section 1 (Introduction). quote: “In addition to these, Claesson, Jelínek and Steingrímsson [13] make a conjecture regarding the number of -avoiders of each length that have a fixed number of inversions, which if proven would yield an improved upper bound of .”
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[BBEPP2017-estimate] loc: arXiv v3 PDF p.2, Section 1 (Introduction). quote: “Conway, Guttmann and Zinn-Justin [14, 15] have analysed the numbers and give a numerical estimate for of .”
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[BBEPP2017-asymptotic] loc: arXiv v3 PDF p.2, Section 1 (Introduction). quote: “They also conjecture that behaves asymptotically as , for certain estimated constants , and .”
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[B04] Bóna, Miklós. A simple proof for the exponential upper bound for some tenacious patterns. Advances in Applied Mathematics 33 (2004), no. 1, 192–198. DOI: 10.1016/j.aam.2003.07.003. Google Scholar
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[B05] Bóna, Miklós. The limit of a Stanley–Wilf sequence is not always rational, and layered patterns beat monotone patterns. J. Combin. Theory Ser. A 110 (2005), no. 2, 223–235. DOI: 10.1016/j.jcta.2004.07.014. Google Scholar. arXiv PDF
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[AERWZ] Albert, M. H.; Elder, M.; Rechnitzer, A.; Westcott, P.; Zabrocki, M. On the Stanley–Wilf limit of 4231-avoiding permutations and a conjecture of Arratia. Adv. Appl. Math. 36 (2006), no. 2, 96–105. DOI: 10.1016/j.aam.2005.05.007. Google Scholar. arXiv PDF
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[CJS12] Claesson, A.; Jelínek, V.; Steingrímsson, E. Upper bounds for the Stanley–Wilf limit of 1324 and other layered patterns. J. Combin. Theory Ser. A 119 (2012), no. 8, 1680–1691. DOI: 10.1016/j.jcta.2012.05.006. Google Scholar. arXiv PDF
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[CJS12-def-Sn] loc: arXiv v1 PDF p.1, Section 1 (Introduction). quote: “For a permutation pattern , let be the set of permutations of length avoiding , and let be the cardinality of .”
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[CJS12-def-Ltau] loc: arXiv v1 PDF p.1, Section 1 (Introduction). quote: “The limit is called the Stanley-Wilf limit for .”
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[CJS12-mt-expbound] loc: arXiv v1 PDF p.1, Section 1 (Introduction). quote: “In 2004, Marcus and Tardos [15] proved the Stanley-Wilf conjecture, stating that, for any pattern , for some constant depending only on .”
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[CJS12-arratia-exists] loc: arXiv v1 PDF p.1, Section 1 (Introduction). quote: “Arratia [3] has shown that this limit exists for any pattern .”
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[CJS12-cond-ub] loc: arXiv v1 PDF p.1, Abstract. quote: “We also conjecture that, for any , the set of -avoiding permutations with inversions contains at least as many permutations of length as those of length . We show that if this is true then the Stanley-Wilf limit for is at most .”
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[B14a] Bóna, Miklós. A new upper bound for 1324-avoiding permutations. Combinatorics, Probability and Computing 23 (2014), no. 5, 717–724. DOI: 10.1017/S0963548314000091. Google Scholar. arXiv PDF
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[B14b] Bóna, Miklós. A new record for 1324-avoiding permutations. European J. Math. 1 (2015), no. 1, 198–206. DOI: 10.1007/s40879-014-0020-6. Google Scholar. arXiv PDF
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[Bev] Bevan, David. Permutations avoiding 1324 and patterns in Łukasiewicz paths. J. London Math. Soc. 92 (2015), no. 1, 105–122. DOI: 10.1112/jlms/jdv020. Google Scholar. arXiv PDF
Progress & source assessment
Repository table (commit 2c1968c, 26 September 2026): best known lower bound 10.27; best known upper bound 13.5. Values marked with an asterisk have minimal verification.
Known upper bounds
| Bound | Reference | Comments |
|---|---|---|
| [B04] | Upper bound recorded in Table 1 of [BBEPP2017]. [BBEPP2017-t1-ub-288] | |
| [CJS12] | Upper bound recorded in Table 1 of [BBEPP2017]. [BBEPP2017-t1-ub-16] | |
| [B14a] | Upper bound recorded in Table 1 of [BBEPP2017]. [BBEPP2017-t1-ub-13.93] | |
| [B14b] | Upper bound recorded in Table 1 of [BBEPP2017]. [BBEPP2017-t1-ub-13.74] | |
| [BBEPP2017] | Current best rigorous upper bound. [BBEPP2017-t1-thiswork] |
Known lower bounds
| Bound | Reference | Comments |
|---|---|---|
| [B05] | Lower bound recorded in Table 1 of BBEPP2017. [BBEPP2017-t1-lb-9] | |
| [AERWZ] | Lower bound recorded in Table 1 of BBEPP2017. [BBEPP2017-t1-lb-9.47] | |
| [Bev] | Lower bound recorded in Table 1 of BBEPP2017. [BBEPP2017-t1-lb-9.81] | |
| [BBEPP2017] | Current best rigorous lower bound. [BBEPP2017-t1-thiswork] |
- [1]Davis, Damek; Ivanisvili, Paata; Tao, Terence (maintainers). Optimization Constants in Mathematics, github.com/teorth/optimizationproblems (commit 2c1968c, 26 September 2026). — Stanley–Wilf limit for the permutation pattern $1324$ ($C_{30}$) linkApache-2.0 (repository license); constant pages reproduced with attribution; repository references retained.
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