a(1) = 3, a(n + 1) = 1 + a(n) + least odd prime factor of a(n).

Terms

a(0) =3a(1) =7a(2) =15a(3) =19a(4) =39a(5) =43a(6) =87a(7) =91a(8) =99a(9) =103a(10) =207a(11) =211a(12) =423a(13) =427a(14) =435a(15) =439a(16) =879a(17) =883a(18) =1767a(19) =1771a(20) =1779a(21) =1783a(22) =3567a(23) =3571a(24) =7143a(25) =7147a(26) =7155a(27) =7159a(28) =14319a(29) =14323