a(n) = (8*n+5)*(8*n+9).

Terms

a(0) =45a(1) =221a(2) =525a(3) =957a(4) =1517a(5) =2205a(6) =3021a(7) =3965a(8) =5037a(9) =6237a(10) =7565a(11) =9021a(12) =10605a(13) =12317a(14) =14157a(15) =16125a(16) =18221a(17) =20445a(18) =22797a(19) =25277a(20) =27885a(21) =30621a(22) =33485a(23) =36477a(24) =39597a(25) =42845a(26) =46221a(27) =49725a(28) =53357a(29) =57117