3x+1 sequence starting at 81.

Terms

a(0) =81a(1) =244a(2) =122a(3) =61a(4) =184a(5) =92a(6) =46a(7) =23a(8) =70a(9) =35a(10) =106a(11) =53a(12) =160a(13) =80a(14) =40a(15) =20a(16) =10a(17) =5a(18) =16a(19) =8a(20) =4a(21) =2a(22) =1a(23) =4a(24) =2a(25) =1a(26) =4a(27) =2a(28) =1a(29) =4