Numbers expressible as a^2 + k b^2 with nonzero integers a,b, for k=2, k=3, k=5 and k=7.

Terms

a(0) =144a(1) =576a(2) =1009a(3) =1129a(4) =1201a(5) =1296a(6) =1801a(7) =1849a(8) =2304a(9) =2521a(10) =2689a(11) =2881a(12) =3049a(13) =3361a(14) =3529a(15) =3600a(16) =3889a(17) =4036a(18) =4201a(19) =4356a(20) =4489a(21) =4516a(22) =4561a(23) =4729a(24) =4804a(25) =5184a(26) =5209a(27) =5569a(28) =5881a(29) =5929