a(n) = Sum_{k=0..floor(n/2)} binomial(2*n+k-1,k) * binomial(2*n+k,n-2*k).

A379084

a(n) = Sum_{k=0..floor(n/2)} binomial(2*n+k-1,k) * binomial(2*n+k,n-2*k).

Terms

    a(0) =1a(1) =2a(2) =10a(3) =62a(4) =394a(5) =2562a(6) =16966a(7) =113794a(8) =770458a(9) =5254658a(10) =36046470a(11) =248449104a(12) =1719175846a(13) =11935608518a(14) =83100064834a(15) =579994824042

External references