a(n) = Sum_{k=0..n} binomial(2*n+2,k) * binomial(2*n-k,n-k).
A386843
a(n) = Sum_{k=0..n} binomial(2*n+2,k) * binomial(2*n-k,n-k).
Terms
- a(0) =1a(1) =6a(2) =39a(3) =268a(4) =1905a(5) =13842a(6) =102123a(7) =761880a(8) =5732325a(9) =43417630a(10) =330620895a(11) =2528772132a(12) =19412942809a(13) =149497184298
External references
- oeis: A386843