a(n) = (2*n-1)^2 * a(n-1) - 3*C(2*n-1,3) * a(n-2) for n>1; a(0) = a(1) = 1.
A002370
a(n) = (2*n-1)^2 * a(n-1) - 3*C(2*n-1,3) * a(n-2) for n>1; a(0) = a(1) = 1.
Terms
- a(0) =1a(1) =1a(2) =6a(3) =120a(4) =5250a(5) =395010a(6) =45197460a(7) =7299452160
External references
- oeis: A002370