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.

A347085 Sum of A129283 and its Dirichlet inverse.

Original entry on oeis.org

2, 0, 0, 9, 0, 24, 0, 21, 16, 36, 0, 22, 0, 48, 48, 49, 0, 34, 0, 36, 64, 72, 0, 63, 36, 84, 56, 50, 0, -26, 0, 113, 96, 108, 96, 102, 0, 120, 112, 101, 0, -30, 0, 78, 76, 144, 0, 156, 64, 90, 144, 92, 0, 126, 144, 139, 160, 180, 0, 203, 0, 192, 104, 257, 168, -38, 0, 120, 192, -34, 0, 230, 0, 228, 124, 134, 192
Offset: 1

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Author

Antti Karttunen, Aug 17 2021

Keywords

Crossrefs

Programs

  • PARI
    up_to = 16384;
    DirInverseCorrect(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = (-u[1]*sumdiv(n, d, if(dA003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A129283(n) = (n + A003415(n));
    v347084 = DirInverseCorrect(vector(up_to,n,A129283(n)));
    A347084(n) = v347084[n];
    A347085(n) = (A129283(n)+A347084(n));

Formula

a(n) = A129283(n) + A347084(n).
For n > 1, a(n) = -Sum_{d|n, 1A129283(d) * A347084(n/d).