a(0)=1, a(n) = least k > a(n-1) such that k*a(n-1) is a triangular number.

Terms

a(0) =1a(1) =3a(2) =5a(3) =9a(4) =17a(5) =33a(6) =45a(7) =72a(8) =143a(9) =152a(10) =303a(11) =420a(12) =451a(13) =603a(14) =952a(15) =1398a(16) =1572a(17) =2408a(18) =3762a(19) =4233a(20) =5880a(21) =6325a(22) =8469a(23) =13384a(24) =20079a(25) =34189a(26) =62769a(27) =82665a(28) =87448a(29) =161037