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 A372445 #6 May 01 2024 16:11:34
%S A372445 7,6,8,12,18,27,21,16,23,18,26,39,30,44,66,99,75,28,42,63,48,71,54,80,
%T A372445 120,180,270,405,152,228,342,513,97,73,55,11,4,6,9,1,1,1,1,1,1,1,1,1,
%U A372445 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1
%N A372445 a(n) = A371092(A372443(n)).
%C A372445 a(n) gives the column index of A372443(n), or equally, of A372444(n) in array A257852.
%H A372445 <a href="/index/3#3x1">Index entries for sequences related to 3x+1 (or Collatz) problem</a>
%F A372445 a(n) = A371092(A372443(n)) = A371092(A372444(n)).
%o A372445 (PARI)
%o A372445 A000265(n) = (n>>valuation(n,2));
%o A372445 A371092(n) = floor((A000265(1+(3*n))+5)/6);
%o A372445 A372443(n) = { my(x=27); while(n, x=A000265(3*x+1); n--); (x); };
%o A372445 A372445(n) = A371092(A372443(n));
%Y A372445 Cf. A257852, A371092, A372443, A372444.
%Y A372445 Column 14 of A372287, column 7 of A371103.
%K A372445 nonn
%O A372445 0,1
%A A372445 _Antti Karttunen_, May 01 2024