Differences of two positive 4th powers.

Terms

a(0) =0a(1) =15a(2) =65a(3) =80a(4) =175a(5) =240a(6) =255a(7) =369a(8) =544a(9) =609a(10) =624a(11) =671a(12) =1040a(13) =1105a(14) =1215a(15) =1280a(16) =1295a(17) =1695a(18) =1776a(19) =2145a(20) =2320a(21) =2385a(22) =2400a(23) =2465a(24) =2800a(25) =3439a(26) =3471a(27) =3840a(28) =4015a(29) =4080