Quadrinomial coefficients.

Terms

a(0) =1a(1) =10a(2) =44a(3) =135a(4) =336a(5) =728a(6) =1428a(7) =2598a(8) =4455a(9) =7282a(10) =11440a(11) =17381a(12) =25662a(13) =36960a(14) =52088a(15) =72012a(16) =97869a(17) =130986a(18) =172900a(19) =225379a(20) =290444a(21) =370392a(22) =467820a(23) =585650a(24) =727155a(25) =895986a(26) =1096200a(27) =1332289a(28) =1609210a(29) =1932416