a(n) = Sum_{k=0..floor((n-3)/2)} T(n,k) * T(n,k+2), with T given by A008315.
A027303
a(n) = Sum_{k=0..floor((n-3)/2)} T(n,k) * T(n,k+2), with T given by A008315.
Terms
- a(0) =2a(1) =5a(2) =34a(3) =98a(4) =496a(5) =1545a(6) =7010a(7) =22924a(8) =98636a(9) =333463a(10) =1393014a(11) =4824350a(12) =19795200a(13) =69818507a(14) =283195638a(15) =1013208668a(16) =4078132240a(17) =14758843463a(18) =59087809638a(19) =215859015800a(20) =860951003152
External references
- oeis: A027303