a(n) = Sum_{i+j+k=n, 0<=i,j,k<=n} (n+2k)!/(i! * j! * (3*k)!).
A092467
a(n) = Sum_{i+j+k=n, 0<=i,j,k<=n} (n+2k)!/(i! * j! * (3*k)!).
Terms
- a(0) =1a(1) =3a(2) =13a(3) =63a(4) =309a(5) =1511a(6) =7373a(7) =35951a(8) =175269a(9) =854455a(10) =4165565a(11) =20307647a(12) =99002389a(13) =482649479a(14) =2352978861a(15) =11471077391a(16) =55922991237a(17) =272631840855
External references
- oeis: A092467