This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A352907 #49 Jul 26 2022 14:03:21 %S A352907 0,3,4,12,15,16,19,107,108,111,114,117,120,123,126,139,140,166,174, %T A352907 177,178,204,212,233,257,263,271,274,277,303,306,319,335,346,349,370, %U A352907 378,381,438,444,465,504,520,523,526,552,555,558,579,592,608,660,681,684 %N A352907 Records in the number of iterations in the 3x+1 sequences required to reach a power of 2. %C A352907 Records of the number of nonpowers of 2 in the sequences 3x+1. %C A352907 Is this a finite sequence? %H A352907 Paolo Xausa, <a href="/A352907/b352907.txt">Table of n, a(n) for n = 1..147</a> (b-file generated using Eric Roosendaal's data and _Omar E. Pol_'s comment in A006877). %H A352907 Eric Roosendaal, <a href="http://www.ericr.nl/wondrous/delrecs.html">3x+1 Delay Records</a> %H A352907 <a href="/index/3#3x1">Index entries for sequences related to 3x+1 (or Collatz) problem</a> %t A352907 f[n_] := -1 + Length @ NestWhileList[If[OddQ[#], 3*# + 1, #/2] &, n, !IntegerQ @ Log[2, #] &]; Union @ FoldList[Max, Array[f, 10^5]] (* _Amiram Eldar_, Apr 08 2022 *) %Y A352907 Records in A208981. %Y A352907 Cf. A352939 (first differences). %Y A352907 Cf. A347270 (gives all 3x+1 sequences). %Y A352907 Cf. A006370, A006877, A014682, A056959, A057716, A347272, A347519, A347532, A353265. %K A352907 nonn %O A352907 1,2 %A A352907 _Omar E. Pol_, Apr 07 2022 %E A352907 More terms from _Alois P. Heinz_, Apr 07 2022