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.

A359169 Dirichlet inverse of the pointwise sum of A349905 (arithmetic derivative of prime shifted n) and A063524 (1, 0, 0, 0, ...).

Original entry on oeis.org

1, -1, -1, -5, -1, -6, -1, -16, -9, -8, -1, -14, -1, -12, -10, -35, -1, -22, -1, -22, -14, -14, -1, 10, -13, -18, -56, -38, -1, -17, -1, -31, -16, -20, -16, 42, -1, -24, -20, -2, -1, -33, -1, -46, -54, -30, -1, 243, -21, -46, -22, -62, -1, -10, -18, -26, -26, -32, -1, 140, -1, -38, -86, 160, -22, -41, -1, -70, -32, -53
Offset: 1

Views

Author

Antti Karttunen, Dec 23 2022

Keywords

Crossrefs

Programs

  • PARI
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A003961(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
    A349905(n) = A003415(A003961(n));
    memoA359169 = Map();
    A359169(n) = if(1==n,1,my(v); if(mapisdefined(memoA359169,n,&v), v, v = -sumdiv(n,d,if(dA349905(n/d)*A359169(d),0)); mapput(memoA359169,n,v); (v)));

Formula

a(1) = 1, and for n > 1, a(n) = -Sum_{d|n, dA349905(n/d) * a(d).
a(n) = A346241(A003961(n)).