Pure numbers in the Collatz (3x+1) iteration. Also called pure hailstone numbers.
0, 1, 3, 6, 7, 9, 12, 15, 18, 19, 21, 24, 25, 27, 30, 33, 36, 37, 39, 42, 43, 45, 48, 51, 54
2 seqfan posts
Fri May 14 13:30:09 CEST 2010 [seqfan] Re: Duplicates? A177729 A177517 A177516