51781

Appears in sequences

• Triangle read by rows, where t(n,1) = 1, t(n,m) = t(n,m-1) + (largest nonprime {1 or composite} in row {n-1}).at n=49A120853
• Expansion of 1/(1 - x/(1 - 25*x^5)^(1/5)).at n=21A373510