a(n) = 2^(2*n-1) * ( binomial(3*n/2,n) + binomial((3*n-1)/2,n) ).

A244039

a(n) = 2^(2*n-1) * ( binomial(3*n/2,n) + binomial((3*n-1)/2,n) ).

Terms

    a(0) =1a(1) =5a(2) =39a(3) =338a(4) =3075a(5) =28770a(6) =274134a(7) =2645844a(8) =25781283a(9) =253068530a(10) =2498678754a(11) =24788450076a(12) =246889978062

External references