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

A378462

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

Terms

    a(0) =1a(1) =1a(2) =5a(3) =28a(4) =157a(5) =891a(6) =5126a(7) =29814a(8) =174869a(9) =1032481a(10) =6128795a(11) =36541220a(12) =218672950a(13) =1312712519a(14) =7901609196a(15) =47673716238a(16) =288226881669

External references