Sum of a square and a triangular number.

Terms

a(0) =0a(1) =1a(2) =2a(3) =3a(4) =4a(5) =5a(6) =6a(7) =7a(8) =9a(9) =10a(10) =11a(11) =12a(12) =14a(13) =15a(14) =16a(15) =17a(16) =19a(17) =21a(18) =22a(19) =24a(20) =25a(21) =26a(22) =28a(23) =29a(24) =30a(25) =31a(26) =32a(27) =35a(28) =36a(29) =37