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 A087664 #9 Feb 18 2021 16:06:51 %S A087664 0,2,1,4,0,5,2,9,0,1,1,1,0,3,3,2,0,4,1,2,0,6,2,7,0,1,1,1,0,5,4,4,0,2, %T A087664 1,3,0,8,2,7,0,1,1,1,0,2,3,6,0,3,1,2,0,2,2,2,0,1,1,1,0,4,5,5,0,2,1,6, %U A087664 0,5,2,4,0,1,1,1,0,4,3,2,0,5,1,2,0,3,2,3,0,1,1,1,0,4,4,6,0,2,1,3,0,3,2,3,0 %N A087664 Consider recurrence b(0) = n/4, b(k) = b(k-1)*floor(b(k-1)); sequence gives number of steps to reach an integer, or -1 if no integer is ever reached. %C A087664 It is conjectured that an integer is always reached if the initial value is >= 2. %H A087664 J. C. Lagarias and N. J. A. Sloane, Approximate squaring (<a href="http://neilsloane.com/doc/apsq.pdf">pdf</a>, <a href="http://neilsloane.com/doc/apsq.ps">ps</a>), Experimental Math., 13 (2004), 113-128. %Y A087664 Cf. A087665 (integer reached), A087667 and A087668 (records), A057016. %K A087664 nonn %O A087664 8,2 %A A087664 _N. J. A. Sloane_, Sep 27 2003 %E A087664 More terms from _John W. Layman_, Sep 27 2003