Numbers congruent to 0 or 3 mod 4.

Terms

a(0) =0a(1) =3a(2) =4a(3) =7a(4) =8a(5) =11a(6) =12a(7) =15a(8) =16a(9) =19a(10) =20a(11) =23a(12) =24a(13) =27a(14) =28a(15) =31a(16) =32a(17) =35a(18) =36a(19) =39a(20) =40a(21) =43a(22) =44a(23) =47a(24) =48a(25) =51a(26) =52a(27) =55a(28) =56a(29) =59