A371245 Number of factorizations of n into factors > 4.

1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 2, 1, 2, 1, 1, 2, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 3, 1, 1, 2, 2, 2, 2, 1, 1, 1, 3, 1, 3, 1, 1, 2, 1, 2, 2, 1, 3, 2, 1, 1, 3, 2, 1, 1, 2, 1, 4, 2, 1

Offset

1,25

Links

Antti Karttunen, Table of n, a(n) for n = 1..20000

Formula

Dirichlet g.f.: Product_{k>=5} 1 / (1 - k^(-s)).

Example

a(60) = 3: 60 = 5*12 = 6*10.

Prog

(PARI) A371245(n, m=n) = if(1==n, 1, my(s=0); fordiv(n, d, if((d>4)&&(d<=m), s += A371245(n/d, d))); (s)); \\ Antti Karttunen, Jan 17 2025

Crossrefs

Cf. A001055, A017899, A185325, A371212, A371243, A371244.

Sequence in context: A107038 A236833 A328511 * A043278 A125238 A380698

Adjacent sequences: A371242 A371243 A371244 * A371246 A371247 A371248

Keyword

nonn

Author

Ilya Gutkovskiy, Mar 16 2024

Status

approved