a(n) = Sum_{k=0..n} (-2)^k * binomial(2n-k,k) * (n-k)!.
A097625
a(n) = Sum_{k=0..n} (-2)^k * binomial(2n-k,k) * (n-k)!.
Terms
- a(0) =-1a(1) =0a(2) =2a(3) =-4a(4) =8a(5) =0a(6) =80a(7) =544a(8) =5248a(9) =53504a(10) =601344a(11) =7339520a(12) =96797696a(13) =1371889664a(14) =20797212672a(15) =335835828224
External references
- oeis: A097625