251216

Appears in sequences

• 5-white numbers: partition digits of n^5 into blocks of 5 starting at right; sum of these 5-digit numbers equals n.at n=28A037045
• Integers k such that phi(prime(k)+1) = phi(prime(k)-1).at n=19A066902
• Triangle, read by rows, where T(n,k) = Sum_{i=k..n-1} T(n-1,i)*T(i+1,k+1) for n>k with T(n,n) = n+1 for n>=0.at n=40A152541
• Wiener index of the n X n black bishop graph.at n=31A292051
• Wiener index of the n X n white bishop graph.at n=30A292059