40340

Appears in sequences

• Triangle read by rows: T(n,k) is the number of Motzkin paths of length n and having k peaks at odd height.at n=56A097891
• If n = p*10^i + q*10^(i-1) + r*10^(i-2) + ... in decimal notation, then a(n) = p!*10^i + q!*10^(i-1) + r!*10^(i-2)+ ... .at n=28A182287
• Numbers k for which k = phi(k') + phi(k''), where phi is the Euler totient function (A000010), k' the arithmetic derivative of k (A003415) and k'' the second arithmetic derivative of k (A068346).at n=17A352332
• The fixed points of A355636.at n=20A355637
• a(n) = Sum_{k=1..n} sigma(n*k).at n=29A372710