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 A280707 #14 May 06 2023 21:32:40
%S A280707 47,2022,1011,337,111548,55774,27887,353,123198,61599,20533,421357694,
%T A280707 210678847,44385566460664754,22192783230332377,1707137171564029,
%U A280707 165918667661,27529004277737692540278,13764502138868846270139,4588167379622948756713,352935952278688365901,3237944516318241889,1577861856421,2489648037916767181800822
%N A280707 Collatz-2 (A063041) trajectory starting at 47.
%C A280707 Will this sequence ever settle into a finite cycle?
%H A280707 Sean A. Irvine, <a href="/A280707/b280707.txt">Table of n, a(n) for n = 0..134</a> (terms 0..41 from Antti Karttunen, terms 42..103 from Hans Havermann)
%F A280707 a(0) = 47 and for n > 1, a(n) = A063041(a(n-1)).
%o A280707 (PARI)
%o A280707 A032742(n) = if(1==n,n,n/vecmin(factor(n)[,1]));
%o A280707 A063041(n) = if(2==n,3,if(isprime(n),1+(precprime(n-1)*n),A032742(n)));
%o A280707 n = 0; k = 47; while(n <= 41, write("b280707.txt", n, " ", k); k = A063041(k); n = n+1);
%Y A280707 Cf. A032742, A063041, A063045, A063046.
%K A280707 nonn
%O A280707 0,1
%A A280707 _Antti Karttunen_, Jan 23 2017