a(n) = least number k such that 2^n is highest in Collatz(3x+1) trajectory of k.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =3a(5) =32a(6) =21a(7) =128a(8) =85a(9) =512a(10) =151a(11) =2048a(12) =1365a(13) =8192a(14) =5461a(15) =32768a(16) =14563a(17) =131072a(18) =87381a(19) =524288a(20) =349525a(21) =2097152a(22) =932067a(23) =8388608a(24) =5592405a(25) =33554432a(26) =22369621a(27) =134217728a(28) =26512143a(29) =536870912