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 A225772 #26 Oct 29 2013 03:39:46 %S A225772 0,4,67,1455,41829,1540566,68342769,3540690574,209612913688, %T A225772 13957423185476,1032436318249157,83993175608836193, %U A225772 7453446303042081363,716451740543945322472,74159075140708643215135 %N A225772 Number of 2-element sets of mapping patterns from n points to themselves; the number of 2-element sets of transformations on n points up to conjugation. %H A225772 J. D. Mitchell, <a href="http://www-groups.mcs.st-andrews.ac.uk/~jamesm/data.php">Semigroups data</a> (contains links to files containing the 2-element sets of transformations on n points up to conjugation) %F A225772 a(n) = A054745(n) - A001372(n). [_James Mitchell_, Oct 29 2013] %Y A225772 Cf. A001372, A224539. %K A225772 nonn %O A225772 1,2 %A A225772 _James Mitchell_, Jul 26 2013 %E A225772 Added more terms, _James Mitchell_, Oct 29 2013