a(n) = ((2*n+2)*(2*n+3) - 1)*a(n-1) + 2*n*(2*n+1)*a(n-2), a(0)=0, a(1)=6.
A206307
a(n) = ((2*n+2)*(2*n+3) - 1)*a(n-1) + 2*n*(2*n+1)*a(n-2), a(0)=0, a(1)=6.
Terms
- a(0) =0a(1) =6a(2) =246a(3) =17718a(4) =1948974a(5) =304039950a(6) =63848389494
External references
- oeis: A206307