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 A072147 #8 Jul 11 2015 00:37:27 %S A072147 0,1,2,6,7,12,13,18,25,40,45,47,48,49,55,56,60,62,63,64,66,71,72,75, %T A072147 78,81,106,108,111,112,114,115,119,121,122,130,132,133,135,147,148, %U A072147 149,151,156 %N A072147 Records for the length of the preperiodic part of the 'Reverse and Subtract' trajectories. %C A072147 Successive maxima in sequence A072137. A072146 gives the corresponding starting points. - This sequence is a weak analog of A065199, which uses 'Reverse and Add'. %e A072147 6 is a record, since the preperiodic part of the trajectory of 13 has length 6 and for k < 13 the preperiodic part has a smaller length (at most 2). %Y A072147 Cf. A072137, A072146, A065199. %K A072147 base,more,nonn %O A072147 1,3 %A A072147 _Klaus Brockhaus_, Jun 24 2002 %E A072147 a(18) inserted, a(25) corrected, a(29) through a(44) added by Alexander Pesch (alex-physics(AT)gmx.net), May 29 2007 %E A072147 Edited by _N. J. A. Sloane_, Dec 01 2007