A225772 - OEIS

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.

%I #26 Oct 29 2013 03:39:46

%S 0,4,67,1455,41829,1540566,68342769,3540690574,209612913688,

%T 13957423185476,1032436318249157,83993175608836193,

%U 7453446303042081363,716451740543945322472,74159075140708643215135

%N 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 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 a(n) = A054745(n) - A001372(n). [_James Mitchell_, Oct 29 2013]

%Y Cf. A001372, A224539.

%K nonn

%O 1,2

%A _James Mitchell_, Jul 26 2013

%E Added more terms, _James Mitchell_, Oct 29 2013