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.

0, 4, 67, 1455, 41829, 1540566, 68342769, 3540690574, 209612913688, 13957423185476, 1032436318249157, 83993175608836193, 7453446303042081363, 716451740543945322472, 74159075140708643215135

Offset

1,2

Links

Table of n, a(n) for n=1..15.

J. D. Mitchell, Semigroups data (contains links to files containing the 2-element sets of transformations on n points up to conjugation)

Formula

a(n) = A054745(n) - A001372(n). [James Mitchell, Oct 29 2013]

Crossrefs

Cf. A001372, A224539.

Sequence in context: A225940 A003360 A367121 * A329478 A241001 A308382

Adjacent sequences: A225769 A225770 A225771 * A225773 A225774 A225775

Keyword

nonn

Author

James Mitchell, Jul 26 2013

Extensions

Added more terms, James Mitchell, Oct 29 2013

Status

approved