A295595 - OEIS

%I #18 Feb 16 2018 10:21:21

%S 36,3924,6012,7596,8172,11412,12564,12708,14004,15156,15804,16164,

%T 19692,20556,21564,22068,22212,26388,27684,30924,34812,35172,35388,

%U 39492,41508,41868,42732,43812,45324,45972,46836,46908,47052,49212,52092,53388,53604,53748,58932

%N Numbers k such that Bernoulli number B_{k} has denominator 1919190.

%C 1919190 = 2*3*5*7*13*19*37.

%C All terms are multiples of a(1) = 36.

%C For these numbers numerator(B_{k}) mod denominator(B_{k}) = 1280537.

%H Seiichi Manyama, <a href="/A295595/b295595.txt">Table of n, a(n) for n = 1..1000</a>

%e Bernoulli B_{36} is

%e -26315271553053477373/1919190, hence 36 is in the sequence.

%p with(numtheory): P:=proc(q, h) local n;  for n from 2 by 2 to q do

%p if denom(bernoulli(n))=h then print(n); fi; od; end: P(10^6,1919190);

%p # Alternative according to _Robert Israel_'s code in A282773:

%p with(numtheory): filter:= n ->

%p select(isprime, map(`+`, divisors(n), 1)) = {2, 3, 5, 7, 13, 19, 37}:

%p select(filter, [seq(i, i=1..10^5)]);

%Y Cf. A282773.

%K nonn,easy

%O 1,1

%A _Paolo P. Lava_, Nov 24 2017