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.

A331289 a(n) = A329348(n) - A001222(n).

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, -2, -1, 0, 0, 1, 0, 0, 4, -2, 0, -1, 0, 1, 4, 0, 0, -1, 0, 0, -2, 1, 0, 2, 0, -4, 4, 0, 6, 0, 0, 0, 4, -3, 0, -2, 0, 1, -2, 0, 0, -4, -1, 1, 4, 1, 0, -2, 2, 4, 4, 0, 0, -1, 0, 0, 0, -4, 11, 9, 0, 1, 4, 2, 0, -2, 0, 0, 2, 1, 0, 9, 0, -3, -3, 0, 0, -2, 9, 0, 4, 4, 0, -2, 4, 1, 4, 0, 5, -4, 0, -1, 7, -3, 0, 9, 0, 4, 1
Offset: 1

Views

Author

Antti Karttunen, Jan 15 2020

Keywords

Crossrefs

Programs

  • PARI
    A002110(n) = prod(i=1, n, prime(i));
    A331289(n) = if(1==n, 1, my(f=factor(n), p=nextprime(1+vecmax(f[, 1]))); (prod(i=1, #f~, A002110(primepi(f[i, 1]))^(f[i, 2]-(#f~==i)))%p)-bigomega(n));

Formula

a(n) = A329348(n) - A001222(n).
a(n) = (A331188(n) mod A117366(n)) - A001222(n).