Start with i=1 and j=2. Concatenate i and j, get k = floor(ij/j), concatenate j and k, etc.

Terms

a(0) =1a(1) =2a(2) =6a(3) =4a(4) =16a(5) =26a(6) =62a(7) =42a(8) =148a(9) =284a(10) =522a(11) =545a(12) =958a(13) =569a(14) =1684a(15) =3379a(16) =4984a(17) =6780a(18) =7352a(19) =9222a(20) =7973a(21) =11567a(22) =68929a(23) =16782a(24) =410732a(25) =40859a(26) =1005243a(27) =406459a(28) =2473172a(29) =1643473