a(n) = (-1)^(n+1)/3/(2n+1) * Sum_{k=0..n} 16^k*B(2k)*C(2n+1,2k) where B(k) denotes the k-th Bernoulli number.
A076552
a(n) = (-1)^(n+1)/3/(2n+1) * Sum_{k=0..n} 16^k*B(2k)*C(2n+1,2k) where B(k) denotes the k-th Bernoulli number.
Terms
- a(0) =1a(1) =1a(2) =21a(3) =461a(4) =16841a(5) =900921a(6) =66453661a(7) =6463837381a(8) =801626558481
External references
- oeis: A076552