a(n)=((-1)^n/6)*sum_{i1+i2+i3+i4=2n} ((2*n)!/(i1! i2! i3! i4!))*B(i1+i2+i3) where B are the Bernoulli numbers.
A124135
a(n)=((-1)^n/6)*sum_{i1+i2+i3+i4=2n} ((2*n)!/(i1! i2! i3! i4!))*B(i1+i2+i3) where B are the Bernoulli numbers.
Terms
- a(0) =0a(1) =0a(2) =3a(3) =46a(4) =1041a(5) =32592a(6) =1375919a(7) =75858738a(8) =5309829837a(9) =460680712084
External references
- oeis: A124135