A079295 - OEIS

A079295

(D(p)-6)/(12p) where D(p) denotes the denominator of the 2p-th Bernoulli number and p runs through the primes.

1, 1, 1, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0

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OFFSET

1,1

COMMENTS

If p is a Sophie Germain prime (A005384) then denominator(B(2p))= 6*(2p+1).

LINKS

Table of n, a(n) for n=1..95.

FORMULA

a(A053176(n))=0; a(A005384(n))=1.

a(n) = pi(2*prime(n) + 1) - pi(2*prime(n)), where pi(n) = A000720(n) and prime(n) = A000040(n). - Ridouane Oudra, Sep 02 2019

MATHEMATICA

dbn[n_]:=Module[{d=Denominator[BernoulliB[2n]]}, (d-6)/(12n)]; dbn/@ Prime[ Range[100]] (* Harvey P. Dale, May 19 2012 *)