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 A375280 #14 Aug 16 2024 04:28:08
%S A375280 1,2,3,4,16,6,52,8,9,16,52,12,40,52,16,16,52,18,88,20,52,52,160,24,88,
%T A375280 40,27,52,88,30,9232,32,52,52,160,36,112,88,40,40,9232,52,196,52,45,
%U A375280 160,9232,48,148,88,52,52,160,54,9232,56,88,88,304,60,184,9232,63
%N A375280 Largest value in the trajectory of n in the A375265 map.
%C A375280 By definition the trajectory ends when 1 is reached, so a(1) = 1.
%H A375280 Paolo Xausa, <a href="/A375280/b375280.txt">Table of n, a(n) for n = 1..10000</a>
%H A375280 <a href="/index/3#3x1">Index entries for sequences related to 3x+1 (or Collatz) problem</a>.
%F A375280 a(n) = max{A375266(n,k) for 1 <= k <= A375267(n) + 1}.
%e A375280 a(10) = 16 because 16 is the largest value in the trajectory 10 -> 5 -> 16 -> 8 -> 4 -> 2 -> 1.
%t A375280 A375265[n_] := Which[Divisible[n, 3], n/3, Divisible[n, 2], n/2, True, 3*n + 1];
%t A375280 Array[Max[NestWhileList[A375265, #, # > 1 &]] &, 100]
%Y A375280 Cf. A375265, A375266, A375267.
%Y A375280 Cf. A025586, A365478.
%K A375280 nonn,easy
%O A375280 1,2
%A A375280 _Paolo Xausa_, Aug 09 2024