55029

Appears in sequences

• Indices of primes in sequence defined by A(0) = 61, A(n) = 10*A(n-1) + 81 for n > 0.at n=31A101541
• Fill an infinite square array by following a spiral around the origin; in the central cell enter a(0)=1; thereafter, in the n-th cell, enter the sum of the entries of those earlier cells that are in the same row or column as that cell.at n=23A334741