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 A131745 #13 Sep 20 2020 01:12:00 %S A131745 4,20,19,2,13,17,13,5,7,13,16,5,15,10,9,16,15,2,1,16,3,4,2,13,4,17,21, %T A131745 1,5,15,5,14,11,4,0,2,13,4,17,21,2,6,5,3,2,14,11,4,0,2,13,4,17,21,14, %U A131745 14,4,17,21,2,6,5,3,0,4,12,5,12,21,1,5,15,10,9,16,15,13,14,4,17 %N A131745 First French version of A131744. %C A131745 Diacritics are ignored when computing the rank of a letter. %C A131745 Spellings used for French numbers: zero, un, deux, trois, quatre, cinq, six, sept, huit, neuf, dix, onze, douze, treize, quatorze, quinze, seize, dix-sept, dix-huit, dix-neuf, vingt, vingt et un, vingt-deux, vingt-trois, vingt-quatre, vingt-cinq. %C A131745 The numbers 18 and 22-25 do not occur in the sequence. - _David Applegate_, Sep 24 2007 %C A131745 There appears to be no analog in Spanish. (The requirement is that the difference between the ranks of the first two letters in the word for the number n should equal n.) - _David Applegate_, Sep 24 2007. There exists such a sequence (namely, 12, 13, 2, 16, 2, 14, 2, 2, 1...) if (as is standard) letter 'ñ' is granted an alphabet position, whereas digraphs such as 'll' are not. - _Álvar Ibeas_, Sep 18 2020 %e A131745 The sequence begins Quatre, vingt, dix-neuf, deux, treize, ... %Y A131745 Cf. A131744, A131746, A130316, A133816, A133817. %K A131745 nonn,word %O A131745 1,1 %A A131745 _Michael Kleber_, Sep 20 2007 %E A131745 More terms from _David Applegate_, Sep 24 2007