Column 2 of triangle A136467 (scaled): a(n) = A136467(n+2,2)/4^n.
A136469
Column 2 of triangle A136467 (scaled): a(n) = A136467(n+2,2)/4^n.
Terms
- a(0) =1a(1) =4a(2) =36a(3) =972a(4) =82692a(5) =22668224a(6) =20480767016
External references
- oeis: A136469