OFFSET
1,1
COMMENTS
498 = 2 * 3 * 83.
All terms are multiples of a(1) = 82.
For these numbers numerator(B_{n}) mod denominator(B_{n}) = 77.
n such that 82 | n but there are no primes p other than 2, 3, 83 such that p-1 | n. - Robert Israel, Mar 07 2017
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
Wikipedia, Von Staudt-Clausen theorem
EXAMPLE
Bernoulli B_{82} is 1677014149185145836823154509786269900207736027570253414881613/498, hence 82 is in the sequence.
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, 498);
# Alternative:
filter:= n ->
select(isprime, map(`+`, numtheory:-divisors(n), 1)) = {2, 3, 83}:
select(filter, [seq(i, i=82..10^5, 82)]); # Robert Israel, Mar 07 2017
MATHEMATICA
Select[82 Range[360], Denominator@ BernoulliB@ # == 498 &] (* Michael De Vlieger, Mar 07 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Paolo P. Lava, Mar 07 2017
EXTENSIONS
More terms from Michael De Vlieger, Mar 07 2017
STATUS
approved