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 A073427 #2 Oct 03 2013 09:31:21 %S A073427 9,252,6813,265,22,603,16290,439839,267,24,657,17748,479205,17761,670, %T A073427 18099,488682,13194423,17763,672,18153,490140,13233789,490153,18166, %U A073427 490491,13243266,357568191,490155,18168,490545,13244724,357607557 %N A073427 Roman numerals for n evaluated as if in Sallows' base 27. %D A073427 M. J. Halm, Sequences (Re)discovered, Mpossibilities 81 (Aug. 2002). %e A073427 a(1) = 18 because 18 is the value of "I" in Sallows' base 27. %Y A073427 Cf. A072959. %K A073427 base,easy,nonn %O A073427 1,1 %A A073427 _Michael Joseph Halm_, Aug 23 2002