A346188 a(1) = 1; a(n+1) = Sum_{d|n} binomial(n,d) * a(n/d).

1, 1, 3, 10, 47, 236, 1482, 10375, 83351, 750412, 7506488, 82571369, 990876614, 12881395983, 180339682057, 2705095261250, 43281525456071, 735785932753208, 13244146802607336, 251638789249539385, 5032775785133933492, 105688291487814923233, 2325142412733663015287

Offset: 1

Author

Ilya Gutkovskiy, Jul 09 2021

Keywords

• nonn

Crossrefs

Cf. A000110, A003238, A056045, A330017, A345136.

Programs

Mathematica

a[1] = 1; a[n_] := a[n] = Sum[Binomial[n - 1, d] a[(n - 1)/d], {d, Divisors[n - 1]}]; Table[a[n], {n, 1, 23}]