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 A091566 #24 Mar 28 2022 08:14:57 %S A091566 10000,500110100015050, %T A091566 1001100150501100500110050011010001505015001001000115050111000150501001 %N A091566 Start with 10000 = DIX MILLE in French; to get the next term, replace each single letter with its equivalent Roman number if there is one; read the new number in French and repeat. %C A091566 The Pfeiffer reference in the links section has nothing to do with this sequence. The A-number, A091566 for this sequence is given in the reference but it is a typo. The reference is relevant to A085628. - _Geoffrey Critzer_, Jul 28 2014 %H A091566 G. Pfeiffer, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL7/Pfeiffer/pfeiffer6.html">Counting Transitive Relations</a>, Journal of Integer Sequences, Vol. 7 (2004), Article 04.3.2. %Y A091566 Cf. A096968, A096973. %K A091566 nonn,word,bref %O A091566 1,1 %A A091566 _Pierre CAMI_, Aug 19 2004