Conjecturally, largest attractor in '3x+(2n+1)' problem.

Terms

a(0) =1a(1) =3a(2) =347a(3) =7a(4) =9a(5) =13a(6) =319a(7) =1041a(8) =23a(9) =19a(10) =21a(11) =41a(12) =1735a(13) =27a(14) =7055a(15) =31a(16) =39a(17) =2429a(18) =37a(19) =957a(20) =41a(21) =43a(22) =3123a(23) =101a(24) =49a(25) =69a(26) =103a(27) =3817a(28) =57a(29) =221