0,2
Table of n, a(n) for n=0..10.
Trinomial[n_, k_] := If[k == 0, 1, Coefficient[(1 + x + x^2)^n, x^k]]; a[n_] := Sum[Trinomial[n, k](n + k)!, {k, 0, 2n}]; Table[a[n], {n, 0, 20}]
Sequence in context: A172944 A277829 A286396 * A054344 A048912 A036411
Adjacent sequences: A174633 A174634 A174635 * A174637 A174638 A174639
nonn
Emanuele Munarini, Jan 25 2011
approved
