Triangle read by rows, T(n, k) (0 <= k <= n) = (-m)^(n-k)*[x^k] KummerU(-n, 1/m, x) for m = 3.

Terms

a(0) =1a(1) =1a(2) =1a(3) =4a(4) =8a(5) =1a(6) =28a(7) =84a(8) =21a(9) =1a(10) =280a(11) =1120a(12) =420a(13) =40a(14) =1a(15) =3640a(16) =18200a(17) =9100a(18) =1300a(19) =65a(20) =1a(21) =58240a(22) =349440a(23) =218400a(24) =41600a(25) =3120a(26) =96a(27) =1a(28) =1106560a(29) =7745920