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.

A331188 Primorial inflation of A052126(n), where A052126(n) = n/(largest prime dividing n).

Original entry on oeis.org

1, 1, 1, 2, 1, 2, 1, 4, 6, 2, 1, 4, 1, 2, 6, 8, 1, 12, 1, 4, 6, 2, 1, 8, 30, 2, 36, 4, 1, 12, 1, 16, 6, 2, 30, 24, 1, 2, 6, 8, 1, 12, 1, 4, 36, 2, 1, 16, 210, 60, 6, 4, 1, 72, 30, 8, 6, 2, 1, 24, 1, 2, 36, 32, 30, 12, 1, 4, 6, 60, 1, 48, 1, 2, 180, 4, 210, 12, 1, 16, 216, 2, 1, 24, 30, 2, 6, 8, 1, 72, 210, 4, 6, 2, 30, 32
Offset: 1

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Author

Antti Karttunen, Jan 14 2020

Keywords

Comments

The primorial inflation of n, A108951(n), divided by its largest squarefree divisor, which is also its largest primorial divisor.

Crossrefs

Programs

  • PARI
    A002110(n) = prod(i=1,n,prime(i));
    A331188(n) = if(1==n, n, my(f=factor(n)); prod(i=1, #f~, A002110(primepi(f[i, 1]))^(f[i, 2]-(#f~==i))));

Formula

a(n) = A108951(A052126(n)).
a(n) = A003557(A108951(n)).
a(n) = A111701(A108951(n)) = A108951(n) / A002110(A061395(n)).
Other identities. For all >= 1:
A000005(a(n)) = A329382(n) = A005361(A108951(n)).
a(n) mod A117366(n) = A329348(n).