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.

A378989 Dirichlet inverse of the Möbius transform of binary weight of n.

Original entry on oeis.org

1, 0, -1, 0, -1, 0, -2, 0, 1, 0, -2, 0, -2, 0, 1, 0, -1, 0, -2, 0, 5, 0, -3, 0, 0, 0, -3, 0, -3, 0, -4, 0, 6, 0, 5, 0, -2, 0, 4, 0, -2, 0, -3, 0, -1, 0, -4, 0, 4, 0, 1, 0, -3, 0, 3, 0, 4, 0, -4, 0, -4, 0, -11, 0, 6, 0, -2, 0, 8, 0, -3, 0, -2, 0, 2, 0, 9, 0, -4, 0, 6, 0, -3, 0, 1, 0, 6, 0, -3, 0, 8, 0, 9, 0, 2, 0, -2, 0, -12, 0, -3, 0, -4, 0, -12
Offset: 1

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Author

Antti Karttunen, Dec 15 2024

Keywords

Crossrefs

Dirichlet inverse of A297115.
Inverse Möbius transform of A378990.
Cf. A000120.

Programs

  • PARI
    A297115(n) = sumdiv(n, d, moebius(n/d)*hammingweight(d));
    memoA378989 = Map();
    A378989(n) = if(1==n,1,my(v); if(mapisdefined(memoA378989,n,&v), v, v = -sumdiv(n,d,if(dA297115(n/d)*A378989(d),0)); mapput(memoA378989,n,v); (v)));

Formula

a(1) = 1, and for n > 1, a(n) = -Sum_{d|n, dA297115(n/d) * a(d).
a(n) = Sum_{d|n} A378990(d).