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.

A369449 a(n) = A003415(gcd(A003415(n), A276086(n))), where A003415 is the arithmetic derivative and A276086 is the primorial base exp-function.

Original entry on oeis.org

0, 1, 0, 0, 0, 0, 1, 0, 1, 5, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 7, 0, 0, 0, 7, 8, 1, 0, 0, 0, 0, 0, 9, 0, 5, 1, 0, 10, 1, 0, 0, 0, 0, 1, 1, 10, 0, 1, 9, 8, 7, 1, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 1, 1, 21, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 21, 0, 0, 0, 5, 0, 0, 0, 1, 8, 1, 12, 0, 0, 1, 1, 1, 14, 5, 0, 0, 1, 8, 12, 0, 1
Offset: 0

Views

Author

Antti Karttunen, Jan 26 2024

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]));
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A369449(n) = A003415(gcd(A003415(n), A276086(n)));

Formula

a(n) = A003415(A327858(n)).