a(n) = Sum_{k=0..floor(n/3)} binomial(n+k,k)^2 * binomial(n-2*k,k).
A383537
a(n) = Sum_{k=0..floor(n/3)} binomial(n+k,k)^2 * binomial(n-2*k,k).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =17a(4) =51a(5) =109a(6) =981a(7) =4209a(8) =12637a(9) =79351a(10) =393493a(11) =1454021a(12) =7686459a(13) =39697057a(14) =166999101a(15) =823144689a(16) =4241896917a(17) =19293138685a(18) =93151760599a(19) =473739765167
External references
- oeis: A383537