A272183 Numbers n such that Bernoulli number B_{n} has denominator 330.

20, 340, 1220, 1420, 2020, 2980, 3340, 3940, 4460, 4540, 4580, 5140, 5660, 5780, 6260, 6340, 6620, 6940, 7060, 7580, 7660, 7780, 7940, 8020, 8980, 9140, 9260, 9580, 10420, 10820, 11140, 11380, 11740, 12140, 12340, 12860, 13220, 13540, 14020, 15020, 15140, 15740, 15940, 16540, 16780

Offset: 1

Author

Paolo P. Lava, Apr 22 2016

Keywords

• nonn

Comments

330 = 2 * 3 * 5 * 11.

All terms are multiple of a(1) = 20.

For these numbers numerator(B_{n}) mod denominator(B_{n}) = 289.

Examples

			Bernoulli B_{20} is -174611/330, hence 20 is in the sequence.
		

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A045979, A051222, A051225, A051226, A051227, A051228, A051229, A051230, A119456, A119480, A249134, A255684, A271634, A271635, A272138, A272139, A272140, A272184, A272185, A272186.

Programs

Maple

with(numtheory): P:=proc(q,h) local n;  for n from 2 by 2 to q do
if denom(bernoulli(n))=h then print(n); fi; od; end: P(10^6,330);

Mathematica

Select[20 Range@ 850, Denominator@ BernoulliB@ # == 330 &] (* Michael De Vlieger, Apr 29 2016 *)

PARI

isok(n) = denominator(bernfrac(n)) == 330; \\ Michel Marcus, Apr 22 2016

Extensions

a(15)-a(29) from Michel Marcus, Apr 22 2016

a(30)-a(45) from Altug Alkan, Apr 22 2016