a(n) = Sum_{k=0..n} binomial(n+3*k+3,k).

A390383

a(n) = Sum_{k=0..n} binomial(n+3*k+3,k).

Terms

    a(0) =1a(1) =8a(2) =64a(3) =531a(4) =4525a(5) =39277a(6) =345433a(7) =3067863a(8) =27452622a(9) =247134150a(10) =2235610238a(11) =20305403848a(12) =185055810669

External references