Which binomial coefficients C(2^n - 1,n) are squarefree?
TheoremDB P11380 · number theory
Inferred from the community field; finer classification has not been reviewed.
Problem statement
Determine all integers for which the binomial coefficient C(2^n-1,n) is squarefree. Decide whether there are finitely many such n and whether the current list n=0,1,2,3,4,6,11,12,21,28,29,31,51,54,55,57 is complete.
Lean 4
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Background
Additional formulation recorded by the source
Classify {n in N : forall primes p, v_p(binomial(2^n-1,n))<=1}, and determine whether this set equals {0,1,2,3,4,6,11,12,21,28,29,31,51,54,55,57}.
Progress & source assessment
Source-reported assessment, retrieved 8 September 2026. Frontier Science has not independently reviewed this status.
Open. No signed Lean verification is attached to this problem or its selected resolution.
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