77401

Appears in sequences

• a(n) = (2*n - 1)*(7*n^2 - 7*n + 3)/3.at n=25A063494
• Smallest base b such that there exist exactly n Wieferich pseudoprimes (composites c satisfying b^(c-1) == 1 (mod c^2)) less than b.at n=16A255885