A069990 - OEIS

A069990

(-1)^(n+1)/5*sum(k=1,2n,C(2n+1,k)*B(k)*5^k) where C(n,k) are the binomial coefficients, B(k) the Bernoulli numbers.

%I #5 Mar 30 2012 18:38:58

%S 1,15,389,17687,1230957,121576879,16166877205,2784640846791,

%T 603078760252733,160399574539581023,51396542533525536741,

%U 19528343388372578867575,8681260357657270101974029

%N (-1)^(n+1)/5*sum(k=1,2n,C(2n+1,k)*B(k)*5^k) where C(n,k) are the binomial coefficients, B(k) the Bernoulli numbers.

%o (PARI) for(n=1,25,print1(-(-1)^n*sum(i=1,2*n,binomial(2*n+1,i)*bernfrac(i)*5^i)/5,","))

%K easy,nonn

%O 1,2

%A _Benoit Cloitre_, May 01 2002