A370580 a(n) = (n-1)! * Sum_{d|n} d/(d-1)!.

1, 3, 5, 22, 29, 546, 727, 18488, 100809, 1164250, 3628811, 208232652, 479001613, 18741602894, 236107872015, 4796881689616, 20922789888017, 1618457192352018, 6402373705728019, 471378116297088020, 6105908234409984021, 153272981387362636822

Offset

1,2

Links

Table of n, a(n) for n=1..22.

Formula

If p is prime, a(p) = p + (p-1)!.

E.g.f.: Sum_{k>0} x^k/k * exp(x^k).

Prog

(PARI) a(n) = (n-1)!*sumdiv(n, d, d/(d-1)!);
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(sum(k=1, N, x^k/k*exp(x^k))))

Crossrefs

Cf. A087906, A370579.

Sequence in context: A280037 A292557 A147442 * A025093 A025112 A203192

Adjacent sequences: A370577 A370578 A370579 * A370581 A370582 A370583

Keyword

nonn,easy

Author

Seiichi Manyama, Feb 23 2024

Status

approved