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 A153247 #4 Mar 31 2012 13:21:17 %S A153247 0,0,1,1,2,1,0,2,1,3,2,0,2,1,3,1,3,3,2,1,0,2,1,4,3,1,3,2,3,1,3,3,2,1, %T A153247 0,2,1,4,3,0,2,1,2,2,4,4,3,3,1,3,2,2,2,0,3,1,2,3,3,2,1,1,0,2,1,5,4,2, %U A153247 4,3,4,2,4,4,3,2,1,3,2,4,3,0,2,1,2,2,4,4,3,3,1,3,2,2,2,0,3,1,2,3,3,2 %N A153247 Number of fleeing trees computed for Catalan bijection A123493. %C A153247 See comments at A153246. Essentially, A123493 does not extend uniquely to an automorphism of infinite binary tree, because its behavior is dependent on whether certain vertices of a finite binary tree are leaves (terminal nodes) or not. Similarly for bijections like A127387 and A127379. %o A153247 (MIT Scheme:) (define (A153247 n) (count-fleeing-trees n A123493)) %Y A153247 Cf. A153248. %K A153247 nonn %O A153247 0,5 %A A153247 _Antti Karttunen_, Dec 22 2008 %E A153247 Edited by _Charles R Greathouse IV_, May 13 2010