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 A087972 #9 Jun 04 2024 01:26:31 %S A087972 2,4,16,52,9232,244,9232,2464,10528,19684,88576,2270104,1008916, %T A087972 1594324,7174456,65451076,64570084,129140164,1570824736,1961316232, %U A087972 8825923024,10460353204,47071589416,105911076184,423644304724,66034034786644 %N A087972 Maximal term in Collatz-iteration started at 3^n+1. %H A087972 Amiram Eldar, <a href="/A087972/b087972.txt">Table of n, a(n) for n = 0..1000</a> %F A087972 a(n) = A025586(3^n+1). %Y A087972 Cf. A025586, A087701, A087973. %K A087972 nonn %O A087972 0,1 %A A087972 _Labos Elemer_, Sep 24 2003 %E A087972 Offset changed to 0 and a(0) prepended by _Amiram Eldar_, Jun 04 2024