Triangular numbers together with squares (excluding 0).

Terms

a(0) =1a(1) =3a(2) =4a(3) =6a(4) =9a(5) =10a(6) =15a(7) =16a(8) =21a(9) =25a(10) =28a(11) =36a(12) =45a(13) =49a(14) =55a(15) =64a(16) =66a(17) =78a(18) =81a(19) =91a(20) =100a(21) =105a(22) =120a(23) =121a(24) =136a(25) =144a(26) =153a(27) =169a(28) =171a(29) =190