C24 is the Komlós discrepancy constant (often denoted K).
For a real matrix A∈Rm×n, define its (sign) discrepancy by
disc(A) := x∈{−1,1}nmin ∥Ax∥∞.
For each n≥1, define the dimension-n Komlós discrepancy
Kn := sup{disc(A): A∈Rn×n and ∥A∗j∥2≤1 for all columns j}.
Finally, define
C24 := n≥1supKn ∈[0,∞].
The Komlós conjecture asserts that C24<∞ (i.e. Kn=O(1) as n→∞).