114930

Appears in sequences

• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (Lucas numbers), t = (odd natural numbers).at n=28A024473
• Numbers k such that sigma(phi(k)) = phi(sigma(k)).at n=23A033632
• Numbers k such that phi(2*sigma(k)) = 2*sigma(phi(k)).at n=27A067709
• Numbers k such that sigma(phi(k)) divides phi(sigma(k)).at n=37A073858
• Numbers k such that sigma(phi(k)) == phi(sigma(k)) (mod k), that is, A033632(k)/k is an integer.at n=25A092584
• Number of regular tetrahedra in an n-node-per-edge tetrahedral grid.at n=30A269747
• Numbers k such that Bernoulli number B_{k} has denominator 272118.at n=23A295594