cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A378440 Dirichlet inverse of Möbius transform of A033630, where A033630 is the number of partitions of n into distinct divisors of n.

Original entry on oeis.org

1, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, -1, 0, -1, 0, 0, 0, -3, 0, 0, 0, -1, 0, -2, 0, 0, 0, 0, 0, -3, 0, 0, 0, -2, 0, -1, 0, 0, 0, 0, 0, -5, 0, 0, 0, 0, 0, -1, 0, -1, 0, 0, 0, -29, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, -19, 0, 0, 0, 0, 0, 0, 0, -3, 0, 0, 0, -21, 0, 0, 0, -1, 0, -19, 0, 0, 0, 0, 0, -11, 0, 0, 0, -1
Offset: 1

Views

Author

Antti Karttunen, Nov 27 2024

Keywords

Comments

Equally, inverse Möbius transform of A378437, which is the Dirichlet inverse of A033630.

Crossrefs

Inverse Möbius transform of A378437.
Dirichlet inverse of A378439.
Cf. A033630.

Programs

  • PARI
    A033630(n) = if(!n, 1, my(p=1); fordiv(n, d, p *= (1 + 'x^d)); polcoeff(p, n));
    A378439(n) = sumdiv(n, d, moebius(n/d)*A033630(d));
    memoA378440 = Map();
    A378440(n) = if(1==n,1,my(v); if(mapisdefined(memoA378440,n,&v), v, v = -sumdiv(n,d,if(dA378439(n/d)*A378440(d),0)); mapput(memoA378440,n,v); (v)));

Formula

a(1) = 1, and for n > 1, a(n) = -Sum_{d|n, dA378439(n/d) * a(d).
a(n) = Sum_{d|n} A378437(d).