If a, b in sequence, so is a*b+1.

Terms

a(0) =2a(1) =5a(2) =11a(3) =23a(4) =26a(5) =47a(6) =53a(7) =56a(8) =95a(9) =107a(10) =113a(11) =116a(12) =122a(13) =131a(14) =191a(15) =215a(16) =227a(17) =233a(18) =236a(19) =245a(20) =254a(21) =263a(22) =266a(23) =281a(24) =287a(25) =383a(26) =431a(27) =455a(28) =467a(29) =473