Number of partitions of 3n into at most 4 parts.

Terms

a(0) =1a(1) =3a(2) =9a(3) =18a(4) =34a(5) =54a(6) =84a(7) =120a(8) =169a(9) =225a(10) =297a(11) =378a(12) =478a(13) =588a(14) =720a(15) =864a(16) =1033a(17) =1215a(18) =1425a(19) =1650a(20) =1906a(21) =2178a(22) =2484a(23) =2808a(24) =3169a(25) =3549a(26) =3969a(27) =4410a(28) =4894a(29) =5400