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 A171230 #10 Aug 06 2014 16:12:50 %S A171230 0,1,11,11,111,111,111,111,1111,1111,1111,1111,1111,1111,1111,1111, %T A171230 11111,11111,11111,11111,11111,11111,11111,11111,11111,11111,11111, %U A171230 11111,11111,11111,11111,11111,111111,111111,111111,111111,111111 %N A171230 a(n) = 0+1+2+...+n in lunar arithmetic in base 2 written in base 2. %H A171230 D. Applegate, M. LeBrun and N. J. A. Sloane, <a href="http://arxiv.org/abs/1107.1130">Dismal Arithmetic</a> [Note: we have now changed the name from "dismal arithmetic" to "lunar arithmetic" - the old name was too depressing] %H A171230 <a href="/index/Di#dismal">Index entries for sequences related to dismal (or lunar) arithmetic</a> %Y A171230 Cf. A003817. %K A171230 nonn,base %O A171230 0,3 %A A171230 _N. J. A. Sloane_, Oct 02 2010