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 A071156 #14 Mar 27 2018 11:00:41 %S A071156 0,1,3,5,9,11,15,17,23,33,35,39,41,47,57,59,63,65,71,87,89,95,119,153, %T A071156 155,159,161,167,177,179,183,185,191,207,209,215,239,273,275,279,281, %U A071156 287,297,299,303,305,311,327,329,335,359,417,419,423,425,431,447,449 %N A071156 Apart from the initial term (0), lists all integers whose factorial expansion ends with 1 (i.e., are odd numbers), do not contain a digit zero and each successive digit to the left is at most one greater than the preceding digit. %C A071156 a(n) = A085198(A014486(n)) = A071155(A057164(n)). Catalan numbers A000108(n) gives the number of terms whose factorial expansion contain n digits. %C A071156 0 is included by considering it to have the empty string as its factorial base representation. - _Franklin T. Adams-Watters_, Jun 28 2006 %Y A071156 The beginning of this sequence expanded in the factorial number system: A071158. Inverse function: A085199. First differences: A085191. %Y A071156 Cf. A000108 (row lengths), A071155, A120696. %K A071156 base,nonn,tabf %O A071156 0,3 %A A071156 _Antti Karttunen_, May 14 2002