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Numbers n such that Bernoulli number B_{n} has denominator 330.
27

%I #28 Apr 29 2016 09:28:44

%S 20,340,1220,1420,2020,2980,3340,3940,4460,4540,4580,5140,5660,5780,

%T 6260,6340,6620,6940,7060,7580,7660,7780,7940,8020,8980,9140,9260,

%U 9580,10420,10820,11140,11380,11740,12140,12340,12860,13220,13540,14020,15020,15140,15740,15940,16540,16780

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

%C 330 = 2 * 3 * 5 * 11.

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

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

%H Seiichi Manyama, <a href="/A272183/b272183.txt">Table of n, a(n) for n = 1..1000</a>

%e Bernoulli B_{20} is -174611/330, hence 20 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(10^6,330);

%t Select[20 Range@ 850, Denominator@ BernoulliB@ # == 330 &] (* _Michael De Vlieger_, Apr 29 2016 *)

%o (PARI) isok(n) = denominator(bernfrac(n)) == 330; \\ _Michel Marcus_, Apr 22 2016

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

%K nonn

%O 1,1

%A _Paolo P. Lava_, Apr 22 2016

%E a(15)-a(29) from _Michel Marcus_, Apr 22 2016

%E a(30)-a(45) from _Altug Alkan_, Apr 22 2016