a(n)=(-1)^(n+1)*(5/4)*(25^n-1)*B(2n) where B(k) denotes the k-th Bernoulli number.

A090644

a(n)=(-1)^(n+1)*(5/4)*(25^n-1)*B(2n) where B(k) denotes the k-th Bernoulli number.

Terms

    a(0) =0a(1) =5a(2) =26a(3) =465a(4) =16276a(5) =924775a(6) =77244126a(7) =8900960285

External references