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

Terms

a(0) =2a(1) =3a(2) =5a(3) =8a(4) =9a(5) =14a(6) =15a(7) =17a(8) =23a(9) =24a(10) =26a(11) =27a(12) =29a(13) =33a(14) =39a(15) =41a(16) =44a(17) =45a(18) =47a(19) =50a(20) =51a(21) =53a(22) =57a(23) =63a(24) =65a(25) =68a(26) =69a(27) =71a(28) =74a(29) =77