A381515 a(n) = Sum_{j=1..n} Stirling2(n-1,j-1) * a(n-j) for n>=1, starting with a(0) = 1.

1, 1, 1, 2, 5, 16, 71, 432, 3446, 35805, 493247, 9055817, 219034736, 6924788187, 287364757172, 15747872749912, 1138063678023858, 107917571120653077, 13417659577126888599, 2194989270698166806727, 473329783091262653789042, 134287984058139116699933228

Offset: 0

Author

Alois P. Heinz, Feb 25 2025

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..129

Crossrefs

Cf. A000110, A008277, A048993, A308444.

Programs

Maple

a:= proc(n) option remember; `if`(n=0, 1,
      add(a(n-j)*Stirling2(n-1, j-1), j=1..n))
    end:
seq(a(n), n=0..23);