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.

A341835 Dirichlet g.f.: 1 / zeta(s)^9.

Original entry on oeis.org

1, -9, -9, 36, -9, 81, -9, -84, 36, 81, -9, -324, -9, 81, 81, 126, -9, -324, -9, -324, 81, 81, -9, 756, 36, 81, -84, -324, -9, -729, -9, -126, 81, 81, 81, 1296, -9, 81, 81, 756, -9, -729, -9, -324, -324, 81, -9, -1134, 36, -324, 81, -324, -9, 756, 81, 756, 81, 81
Offset: 1

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Author

Ilya Gutkovskiy, Feb 21 2021

Keywords

Comments

Dirichlet inverse of A111219.

Crossrefs

Programs

  • Mathematica
    a[1] = 1; a[n_] := Times @@ ((-1)^#[[2]] Binomial[9, #[[2]]] &/@ FactorInteger[n]); Table[a[n], {n, 58}]
  • PARI
    for(n=1, 100, print1(direuler(p=2, n, (1 - X)^9)[n], ", ")) \\ Vaclav Kotesovec, Feb 22 2021

Formula

Multiplicative with a(p^e) = (-1)^e * binomial(9, e).
a(1) = 1; a(n) = -Sum_{d|n, d < n} tau_9(n/d) * a(d).