a(n) = n*(n + 5)*(n + 7)*(n + 10)/24 + 1.

Terms

a(0) =1a(1) =23a(2) =64a(3) =131a(4) =232a(5) =376a(6) =573a(7) =834a(8) =1171a(9) =1597a(10) =2126a(11) =2773a(12) =3554a(13) =4486a(14) =5587a(15) =6876a(16) =8373a(17) =10099a(18) =12076a(19) =14327a(20) =16876a(21) =19748a(22) =22969a(23) =26566a(24) =30567a(25) =35001a(26) =39898a(27) =45289a(28) =51206a(29) =57682