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 A180513 #21 Aug 06 2014 16:27:47 %S A180513 111111111,111111112,111111113,111111114,111111115,111111116, %T A180513 111111117,111111118,111111119,111111211,111111222,111111223, %U A180513 111111224,111111225,111111226,111111227,111111228,111111229,111111311,111111322,111111333,111111334,111111335,111111336,111111337,111111338,111111339,111111411,111111422,111111433,111111444,111111445,111111446,111111447,111111448,111111449,111111511,111111522 %N A180513 Lunar squares n that can be written as n = i*i in more than one way. %H A180513 N. J. A. Sloane, <a href="/A180513/b180513.txt">Table of n, a(n) for n = 1..6561</a> %H A180513 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] %e A180513 11011*11011 = 11111*11111 = 111111111. %Y A180513 Cf. A087019, A181319. %K A180513 nonn %O A180513 1,1 %A A180513 _David Applegate_, _Marc LeBrun_ and _N. J. A. Sloane_, Jan 21 2011