Positive numbers that are the sum of 2 squares or 3 times a square.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =8a(6) =9a(7) =10a(8) =12a(9) =13a(10) =16a(11) =17a(12) =18a(13) =20a(14) =25a(15) =26a(16) =27a(17) =29a(18) =32a(19) =34a(20) =36a(21) =37a(22) =40a(23) =41a(24) =45a(25) =48a(26) =49a(27) =50a(28) =52a(29) =53