a(n) = (7*n^2 + 15*n + 2) / 2.

Terms

a(0) =1a(1) =12a(2) =30a(3) =55a(4) =87a(5) =126a(6) =172a(7) =225a(8) =285a(9) =352a(10) =426a(11) =507a(12) =595a(13) =690a(14) =792a(15) =901a(16) =1017a(17) =1140a(18) =1270a(19) =1407a(20) =1551a(21) =1702a(22) =1860a(23) =2025a(24) =2197a(25) =2376a(26) =2562a(27) =2755a(28) =2955a(29) =3162