

A060412


In the '3x+1' problem, these values for the starting value set new records for the "dropping time", number of steps to reach a lower value than the start.


17



2, 3, 7, 27, 703, 10087, 35655, 270271, 362343, 381727, 626331, 1027431, 1126015, 8088063, 13421671, 20638335, 26716671, 56924955, 63728127, 217740015, 1200991791, 1827397567, 2788008987, 12235060455
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OFFSET

1,1


COMMENTS

The (3x+1)/2 steps and the halving steps are counted.  Don Reble, May 13 2006


LINKS

Tomás Oliveira e Silva, Tables


EXAMPLE



MATHEMATICA

dcoll[n_]:=Length[NestWhileList[If[EvenQ[#], #/2, 3#+1]&, n, #>=n&]]; t={max=2}; Do[If[(y=dcoll[n])>max, max=y; AppendTo[t, n]], {n, 3, 1130000, 4}]; t (* Jayanta Basu, May 28 2013 *)


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



