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A095384
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Number of different initial values for 3x+1 trajectories started with initial values not exceeding 2^n and in which the peak values are also not larger than 2^n.
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1
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2, 3, 4, 10, 13, 33, 55, 112, 181, 352, 580, 1072, 2127, 6792, 13067, 25906, 51447, 104575, 208149, 415921, 833109, 1661341, 3328124, 6648354, 13283680, 26533708, 53083687, 106166631, 212243709, 424564626, 848967377, 1698139390
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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EXAMPLE
| n=4: between iv={1,2,...,16} {2,8}U{3,5,6,10,12,16} provides
peak values smaller than or equal with 16, so a[4]=10=A087256(4)+4
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MATHEMATICA
| c[x_]:=c[x]=(1-Mod[x, 2])*(x/2)+Mod[x, 2]*(3*x+1); c[1]=1; fpl[x_]:=FixedPointList[c, x]; {$RecursionLimit=1000; m=0}; Table[Print[{xm-1, m}]; m=0; Do[If[ !Greater[Max[fpl[n]], 2^xm], m=m+1], {n, 1, 2^xm}], {xm, 1, 30}]
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CROSSREFS
| Cf. A087256, A095381, A095382, A095383.
Sequence in context: A193775 A131120 A115195 * A177084 A115899 A183527
Adjacent sequences: A095381 A095382 A095383 * A095385 A095386 A095387
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KEYWORD
| more,nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu), Jun 14 2004
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EXTENSIONS
| a(21)-a(32) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Feb 02 2011
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