a(n) = Sum_{k=0..n-1} binomial(4*k+1,k) * binomial(4*n-4*k,n-k-1).

A386612

a(n) = Sum_{k=0..n-1} binomial(4*k+1,k) * binomial(4*n-4*k,n-k-1).

Terms

    a(0) =0a(1) =1a(2) =13a(3) =142a(4) =1464a(5) =14689a(6) =145154a(7) =1420812a(8) =13818784a(9) =133793940a(10) =1291073809a(11) =12426782294a(12) =119371355672

External references