This site is supported by donations to The OEIS Foundation.

 Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A095383 Number of different initial values for 3x+1 trajectories started with initial values not exceeding 2^n and in which the peak values are larger than 2^n. 1
 0, 1, 4, 6, 19, 31, 73, 144, 331, 672, 1468, 3024, 6065, 9592, 19701, 39630, 79625, 157569, 316139, 632655, 1264043, 2532963, 5060484, 10128862, 20270752, 40575156, 81134041, 162268825, 324627203, 649177198, 1298516271, 2596827906 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS EXAMPLE n=4: between iv={1,2,...,16} {7,9,11,13,14,15} provides peak values larger than 16, so a[4]=6. 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}] CROSSREFS Cf. A087256, A095381, A095382, A095384. Sequence in context: A034189 A024697 A024874 * A116383 A026521 A222379 Adjacent sequences:  A095380 A095381 A095382 * A095384 A095385 A095386 KEYWORD nonn AUTHOR Labos Elemer, Jun 14 2004 EXTENSIONS a(22)-a(32) from Donovan Johnson, Feb 02 2011 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 17 10:14 EST 2018. Contains 318193 sequences. (Running on oeis4.)