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 A102093 #2 Mar 31 2012 13:46:51 %S A102093 1,3,4,6,7,9,20,31,40,51,60,71,80,91,201,300,310,411,421,500,510,611, %T A102093 621,700,710,811,821,900,910,2110,2112,2114,2116,2118,2130,2132,2134, %U A102093 2136,2138,2150,2152,2154,2156,2158,2170,2172,2174,2176,2178,2190 %N A102093 Slowest increasing sequence where the digits, taken one by one, show the pattern odd/odd/even/even/odd/odd/even/even... Only the terms < 300 differ from A098161. %Y A102093 Cf. A098161; A097962. %K A102093 base,easy,nonn %O A102093 1,2 %A A102093 _Eric Angelini_, Feb 13 2005