A344370 Dirichlet g.f.: Product_{k>=2} (1 + k^(1-s)).

1, 2, 3, 4, 5, 12, 7, 16, 9, 20, 11, 36, 13, 28, 30, 32, 17, 54, 19, 60, 42, 44, 23, 120, 25, 52, 54, 84, 29, 150, 31, 96, 66, 68, 70, 180, 37, 76, 78, 200, 41, 210, 43, 132, 135, 92, 47, 336, 49, 150, 102, 156, 53, 270, 110, 280, 114, 116, 59, 540

Offset: 1

Author

Ilya Gutkovskiy, May 16 2021

Keywords

• nonn

Crossrefs

Cf. A022629, A045778, A050368, A050369, A224892, A344368, A344369.

Programs

Mathematica

T[m_, 1] := 1; T[1, n_] := 0; T[1, 1] := 1; T[0, n_] := 0; T[m_, n_] := T[m, n] = Total[T[# - 1, n/#] & /@ Select[Divisors[n], # <= m &]]; A045778[n_] := T[n, n]; Table[n A045778[n], {n, 60}]

Formula

a(n) = n * A045778(n).