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.

A373148 a(n) = A276085(n) mod A003415(n), where A003415 is the arithmetic derivative and A276085 is the primorial base log-function.

Original entry on oeis.org

0, 0, 2, 0, 3, 0, 3, 4, 0, 0, 4, 0, 4, 0, 4, 0, 5, 0, 8, 2, 3, 0, 5, 2, 1, 6, 0, 0, 9, 0, 5, 2, 11, 0, 6, 0, 1, 8, 9, 0, 33, 0, 20, 10, 16, 0, 6, 4, 13, 12, 16, 0, 7, 8, 33, 2, 7, 0, 10, 0, 1, 34, 6, 12, 30, 0, 8, 2, 37, 0, 7, 0, 1, 14, 32, 6, 41, 0, 10, 8, 31, 0, 34, 6, 16, 8, 73, 0, 11, 0, 44, 2, 36, 12, 7, 0, 61
Offset: 2

Views

Author

Antti Karttunen, May 27 2024

Keywords

Crossrefs

Cf. also A373145, A373147, and also A328382.

Programs

  • PARI
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A002110(n) = prod(i=1,n,prime(i));
    A276085(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*A002110(primepi(f[k, 1])-1)); };
    A373148(n) = (A276085(n)%A003415(n));