a(n) = (n^4 + 46*n^3 - 169*n^2 + 146*n + 24)/24.

Terms

a(0) =1a(1) =11a(2) =46a(3) =121a(4) =252a(5) =456a(6) =751a(7) =1156a(8) =1691a(9) =2377a(10) =3236a(11) =4291a(12) =5566a(13) =7086a(14) =8877a(15) =10966a(16) =13381a(17) =16151a(18) =19306a(19) =22877a(20) =26896a(21) =31396a(22) =36411a(23) =41976a(24) =48127a(25) =54901a(26) =62336a(27) =70471a(28) =79346a(29) =89002