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A243628
Odd numbers producing 30 even numbers in the Collatz iteration.
1
185, 187, 191, 541, 545, 551, 557, 561, 563, 575, 607, 1629, 1635, 1637, 1655, 1659, 1671, 1677, 1681, 1683, 1685, 1687, 1725, 1755, 1803, 1821, 1825, 1833, 2007, 2011, 4885, 4917, 4929, 4953, 4963, 4965, 4979, 5015, 5017, 5029, 5041, 5043, 5045, 5061, 5077, 5081, 5091, 5121
OFFSET
1,1
COMMENTS
See row 30 of A199636.
LINKS
MATHEMATICA
Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; t = {}; Do[If[Length[Select[Collatz[n], EvenQ]] == 30, AppendTo[t, n]], {n, 1, 100000, 2}]; t
on30Q[n_]:=Count[NestWhileList[If[EvenQ[#], #/2, 3#+1]&, n, #!=1&], _?EvenQ] ==30; Select[Range[1, 5131, 2], on30Q] (* Harvey P. Dale, Mar 18 2023 *)
CROSSREFS
KEYWORD
nonn,fini,less
AUTHOR
Vincenzo Librandi, Jun 08 2014
STATUS
approved