a(n) = (2*n + 1)*(5*n + 6).

Terms

a(0) =6a(1) =33a(2) =80a(3) =147a(4) =234a(5) =341a(6) =468a(7) =615a(8) =782a(9) =969a(10) =1176a(11) =1403a(12) =1650a(13) =1917a(14) =2204a(15) =2511a(16) =2838a(17) =3185a(18) =3552a(19) =3939a(20) =4346a(21) =4773a(22) =5220a(23) =5687a(24) =6174a(25) =6681a(26) =7208a(27) =7755a(28) =8322a(29) =8909