A166333 The largest prime that divides A027642(n) (the denominator of the Bernoulli number B_n), or 1 if A027642(n) is 1.

1, 2, 3, 1, 5, 1, 7, 1, 5, 1, 11, 1, 13, 1, 3, 1, 17, 1, 19, 1, 11, 1, 23, 1, 13, 1, 3, 1, 29, 1, 31, 1, 17, 1, 3, 1, 37, 1, 3, 1, 41, 1, 43, 1, 23, 1, 47, 1, 17, 1, 11, 1, 53, 1, 19, 1, 29, 1, 59, 1, 61, 1, 3, 1, 17, 1, 67, 1, 5, 1, 71, 1, 73, 1, 3, 1, 5, 1, 79, 1, 41, 1, 83, 1, 43, 1, 3, 1, 89, 1

Offset

0,2

Comments

The largest member of the extended prime list A008578 which divides the denominator of Bernoulli(n).

Essentially A073409 padded with 1's.

Links

Antti Karttunen, Table of n, a(n) for n = 0..16384

Formula

a(n) = A006530(A027642(n)). - Antti Karttunen, Dec 19 2018

Prog

(PARI)
A006530(n) = if(n>1, vecmax(factor(n)[, 1]), 1);
A166333(n) = A006530(denominator(bernfrac(n))); \\ Antti Karttunen, Dec 19 2018

Crossrefs

Cf. A006530, A027642, A073409, A089026, A166120.

Sequence in context: A251758 A250480 A326584 * A322966 A173239 A366154

Adjacent sequences: A166330 A166331 A166332 * A166334 A166335 A166336

Keyword

nonn

Author

Paul Curtz, Oct 12 2009

Extensions

Edited and extended by R. J. Mathar, Oct 21 2009

Name and comment swapped by Antti Karttunen, Dec 19 2018

Status

approved