A305610 a(n) = (-1)^(n-1) + Sum_{d|n, d>1} binomial(a(n/d) + d - 1, d).

1, 0, 2, 0, 2, 3, 2, 0, 6, 3, 2, 11, 2, 3, 12, 0, 2, 38, 2, 11, 14, 3, 2, 90, 8, 3, 68, 11, 2, 127, 2, 0, 18, 3, 16, 1194, 2, 3, 20, 90, 2, 173, 2, 11, 644, 3, 2, 5158, 10, 68, 24, 11, 2, 12762, 20, 90, 26, 3, 2, 12910, 2, 3, 1386, 0, 22, 289, 2, 11, 30, 219, 2

Offset

1,3

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Mathematica

a[n_]:=a[n]=(-1)^(n-1)+Sum[Binomial[a[n/d]+d-1, d], {d, Divisors[n]//Rest}];
Array[a, 40]

Prog

(PARI) A305610(n) = ((-1)^(n-1) + sumdiv(n, d, if(d==1, 0, binomial(A305610(n/d)+d-1, d)))); \\ Antti Karttunen, Dec 05 2021

Crossrefs

Cf. A063834, A196545, A220418, A273866, A273873, A275870, A281145, A281146, A289078, A289079, A289501, A290261, A290971, A291441, A300862-A300866.

Sequence in context: A272800 A104513 A357618 * A220455 A208295 A285721

Adjacent sequences: A305607 A305608 A305609 * A305611 A305612 A305613

Keyword

nonn

Author

Gus Wiseman, Jun 06 2018

Status

approved