a(0)=a(1)=1, a(n) = least k > a(n-1) such that k*a(n-2) is a triangular number.

Terms

a(0) =1a(1) =1a(2) =3a(3) =6a(4) =7a(5) =11a(6) =13a(7) =21a(8) =25a(9) =30a(10) =49a(11) =59a(12) =97a(13) =117a(14) =193a(15) =233a(16) =385a(17) =465a(18) =492a(19) =596a(20) =983a(21) =1191a(22) =1965a(23) =2381a(24) =2516a(25) =4761a(26) =5031a(27) =5761a(28) =6290a(29) =8466