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 A112350 #8 Sep 13 2012 12:04:08 %S A112350 2,1,4,1,4,3,4,1,1,3,2,21,24,21,24,23,24,21,21,23,42,421,424,421,424, %T A112350 423,424,421,421,423,12,121,124,121,124,123,124,121,121,123,42,421, %U A112350 424,421,424,423,424,421,421,423,32,321,324,321,324,323,324,321,321,323,42 %N A112350 Pronunciation tones in Mandarin for the characters in the Chinese word for n. %C A112350 Mandarin Chinese has four tones. The first tone is a flat, high tone. The second tone is a rising tone. The third tone first falls a little and then rises. The fourth tone is a falling tone. %D A112350 Any Chinese dictionary. %H A112350 <a href="/index/Lc#letters">Index entries for sequences related to number of letters in n</a> %e A112350 a(21) = 421 because the characters in the Chinese word for 21, "er shi yi", are pronounced with the fourth, second and first tone, respectively. %Y A112350 Cf. A112348, A112350, A030166. %K A112350 nonn,word %O A112350 0,1 %A A112350 Wei Ji Ma (weijima(AT)gmail.com), Sep 05 2005