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 A161023 #16 Oct 13 2022 14:28:31 %S A161023 35655,106966,53483,160450,80225,240676,120338,60169,180508,90254, %T A161023 45127,135382,67691,203074,101537,304612,152306,76153,228460,114230, %U A161023 57115,171346,85673,257020,128510,64255,192766,96383,289150,144575,433726 %N A161023 Collatz trajectory starting at 35655. %C A161023 35655 = A060412(7); a(A006577(35655)) = a(323) = 1. %C A161023 a(n) = A161021(n-153) for n with 297 <= n <= 323; %C A161023 a(n) = A161022(n-100) for n with 308 <= n <= 323. %C A161023 At step 321 becomes periodic: 4 2 1 4 2 1 4 2 1 ... - _N. J. A. Sloane_, Jul 27 2019 %H A161023 R. Zumkeller, <a href="/A161023/b161023.txt">Table of n, a(n) for n = 0..323</a> %H A161023 <a href="/index/3#3x1">Index entries for sequences related to 3x+1 (or Collatz) problem</a> %H A161023 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,1). %t A161023 NestWhileList[If[EvenQ[#],#/2,3#+1]&,35655,#>1&] (* _Harvey P. Dale_, Apr 28 2016 *) %Y A161023 Cf. A008884. %K A161023 nonn,look,easy %O A161023 0,1 %A A161023 _Reinhard Zumkeller_, Jun 03 2009 %E A161023 Edited by _N. J. A. Sloane_, Jul 27 2019