A328580 a(n) is the largest primorial dividing A276086(n), where A276086 converts the primorial base expansion of n into its prime product form.

1, 2, 1, 6, 1, 6, 1, 2, 1, 30, 1, 30, 1, 2, 1, 30, 1, 30, 1, 2, 1, 30, 1, 30, 1, 2, 1, 30, 1, 30, 1, 2, 1, 6, 1, 6, 1, 2, 1, 210, 1, 210, 1, 2, 1, 210, 1, 210, 1, 2, 1, 210, 1, 210, 1, 2, 1, 210, 1, 210, 1, 2, 1, 6, 1, 6, 1, 2, 1, 210, 1, 210, 1, 2, 1, 210, 1, 210, 1, 2, 1, 210, 1, 210, 1, 2, 1, 210, 1, 210

Offset: 0

Author

Antti Karttunen, Oct 20 2019

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 0..2559
• Index entries for sequences related to primorial base

Crossrefs

Cf. A002110, A053589, A276086, A326810, A328475, A328476, A328570.

Programs

PARI

A328580(n) = { my(i=1, p=2, pr=1); while(n && (n%p), pr *= p; n = n\p; p = nextprime(1+p)); (pr); };

Formula

a(n) = A053589(A276086(n)).

a(n) = A002110(A328570(n)-1).

a(n) = A276086(n) / A328475(n).

a(n) = A276086(n) - A328476(n).

A328476(n) / a(n) = A328475(n) - 1.