3x + 1 sequence beginning at 15.

Terms

a(0) =15a(1) =46a(2) =23a(3) =70a(4) =35a(5) =106a(6) =53a(7) =160a(8) =80a(9) =40a(10) =20a(11) =10a(12) =5a(13) =16a(14) =8a(15) =4a(16) =2a(17) =1a(18) =4a(19) =2a(20) =1a(21) =4a(22) =2a(23) =1a(24) =4a(25) =2a(26) =1a(27) =4a(28) =2a(29) =1