a(n) = Sum_{k=0..[n/2]} binomial((n-k)^2, (n-2*k)*k).
A228837
a(n) = Sum_{k=0..[n/2]} binomial((n-k)^2, (n-2*k)*k).
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =38a(5) =597a(6) =14472a(7) =554653a(8) =44421258a(9) =8933194659
External references
- oeis: A228837