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.

A355945 a(n) = n minus the smallest positive k such that n divides k*A276086(k), where A276086 is primorial base exp-function.

Original entry on oeis.org

0, 1, 1, 0, 0, 4, 0, 0, 6, 5, 0, 8, 0, 7, 10, 0, 0, 15, 0, 12, 7, 11, 0, 16, 15, 13, 18, 0, 0, 25, 0, 0, 22, 17, 28, 32, 0, 19, 13, 32, 0, 28, 0, 0, 40, 23, 0, 32, 14, 40, 34, 0, 0, 45, 44, 24, 19, 29, 0, 52, 0, 31, 42, 0, 52, 55, 0, 0, 46, 63, 0, 56, 0, 37, 65, 0, 44, 52, 0, 64, 54, 41, 0, 56, 68, 43, 58, 0, 0, 85, 52
Offset: 1

Views

Author

Antti Karttunen, Jul 27 2022

Keywords

Crossrefs

Cf. A276086, A324580, A355944, A356151, A356160 (positions of zeros), A356161.

Programs

  • PARI
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A355945(n) = for(k=1, oo, if((k*A276086(k))%n==0, return(n-k)));

Formula

a(n) = n - A355944(n).