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 A220090 #17 Dec 06 2012 23:15:07 %S A220090 245,1,12,14,145,15,124,1245,125,24,10245,101,1012,1014,10145,1015, %T A220090 10124,101245,10125,1024,120245,1201,12012,12014,120145,12015,120124, %U A220090 1201245,120125,12024,140245,1401,14012,14014,140145,14015,140124,1401245 %N A220090 Braille natural numbers (including zero), using "0" as digit concatenation mark. %C A220090 Let "0" be the digit concatenation mark, it can be replaced with a "SPACE" as well. %C A220090 XO OO OO OX OO OO %C A220090 Let us define OO-->1; XO-->2; OO-->3; OO-->4; OX-->5 and OO-->6. %C A220090 OO OO XO OO OO OX %D A220090 L. Braille, Method of writing words, music and plain songs by means of dots, for use by the blind and arranged for them, 1829. %H A220090 PharmaBraille, <a href="http://www.pharmabraille.com/pharmaceutical-braille/braille-alphabet.htm">Pharmabraille</a> %F A220090 Let a(0)=245, a(1)=1, a(2)=12, a(3)=14, a(4)=145, a(5)=15, a(6)=124, a(7)=1245, a(8)=125, a(9)=24, then a(n'_n''_..._n''''') = a(n'0n''0...0n'''''), where any [n]''...' is an element of [0,1,2,3,4,5,6,7,8,9]. %e A220090 a(0)=245, a(8636)=12501240140124, etc. %K A220090 base,easy,nonn %O A220090 1,1 %A A220090 _Marco Ripà_, Dec 04 2012