a(n) = (8*n+3)*(8*n+5).

Terms

a(0) =15a(1) =143a(2) =399a(3) =783a(4) =1295a(5) =1935a(6) =2703a(7) =3599a(8) =4623a(9) =5775a(10) =7055a(11) =8463a(12) =9999a(13) =11663a(14) =13455a(15) =15375a(16) =17423a(17) =19599a(18) =21903a(19) =24335a(20) =26895a(21) =29583a(22) =32399a(23) =35343a(24) =38415a(25) =41615a(26) =44943a(27) =48399a(28) =51983a(29) =55695