The number of odd numbers that require n Collatz (3x+1) iterations to reach 1.

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =0a(5) =1a(6) =0a(7) =2a(8) =0a(9) =2a(10) =0a(11) =2a(12) =2a(13) =4a(14) =4a(15) =6a(16) =5a(17) =7a(18) =8a(19) =14a(20) =14a(21) =19a(22) =22a(23) =30a(24) =36a(25) =48a(26) =60a(27) =79a(28) =94a(29) =118