a(n+2) = (2*n+1)^2*a(n+1) + (2*n+1)*(2*n-1)*a(n) with a(1)=1 and a(2)=2.
A218768
a(n+2) = (2*n+1)^2*a(n+1) + (2*n+1)*(2*n-1)*a(n) with a(1)=1 and a(2)=2.
Terms
- a(0) =1a(1) =2a(2) =21a(3) =555a(4) =27930a(5) =2297295a(6) =280737765a(7) =47773195470
External references
- oeis: A218768