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.

A353418 Dirichlet inverse of A353269.

Original entry on oeis.org

1, 0, 0, -1, 0, 0, 0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, -1, 0, 0, -1, 0, 0, 0, 0, -1, 0, 0, 0, -1, 0, 1, 0, 0, -1, 1, 0, 0, 0, 0, 0, -1, 0, 0, -1, 0, 0, 0, 0, 0, -1, 0, -1, 0, 0, 0, 0, -1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 1, -1, 0, -1, 1, 0, 1, -1, 0, 0, -1, 0, 0, 0, 0, 0, 2
Offset: 1

Views

Author

Antti Karttunen, Apr 19 2022

Keywords

Crossrefs

Programs

  • PARI
    up_to = 65537;
    DirInverseCorrect(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = (-u[1]*sumdiv(n, d, if(dA156552(n) = { my(f = factor(n), p, p2 = 1, res = 0); for(i = 1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p * p2 * (2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); res };
    A353269(n) = (!(A156552(n)%3));
    v353418 = DirInverseCorrect(vector(up_to,n,A353269(n)));
    A353418(n) = v353418[n];

Formula

a(1) = 1; a(n) = -Sum_{d|n, d < n} A353269(n/d) * a(d).
a(n) = A353419(n) - A353269(n).
a(p) = 0 for all primes p.
a(n) = a(A003961(n)) = a(A348717(n)), for all n >= 1.