a(n) = n! * Sum_{k=0..floor(n/3)} (-n)^k * binomial(n-2*k,k)/(n-2*k)!.

A362305

a(n) = n! * Sum_{k=0..floor(n/3)} (-n)^k * binomial(n-2*k,k)/(n-2*k)!.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =-17a(4) =-95a(5) =-299a(6) =12241a(7) =122011a(8) =642433a(9) =-41645015a(10) =-597247199a(11) =-4407324569a(12) =390913189921

External references