130620

Appears in sequences

• Triangle read by rows: S_B(n,k) = "Type B" Stirling numbers of the second kind.at n=47A085483
• Numbers k such that 9*R_(k+2) - 5*10^k is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=6A257038
• Triangle read by rows: T(n,k) is the number of endofunctions on [n] where the difference between the smallest and largest values in the image of the function is k, 0 <= k < n.at n=38A391488