a(n) = 3^(2*n)*(3^(2*n)-1)*Bernoulli(2*n)/(2*n).
A047681
a(n) = 3^(2*n)*(3^(2*n)-1)*Bernoulli(2*n)/(2*n).
Terms
- a(0) =6a(1) =-54a(2) =2106a(3) =-179334a(4) =26414586a(5) =-5957217414
External references
- oeis: A047681
A047681
a(n) = 3^(2*n)*(3^(2*n)-1)*Bernoulli(2*n)/(2*n).