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A239765 Number of pairs of functions (f,g) from a set of n elements into itself satisfying f(f(g(x))) = g(g(g(x))). 0
1, 1, 10, 189, 6304, 315065, 21848976, 1992930037 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..7.

CROSSREFS

Cf. A181162.

Sequence in context: A211102 A121973 A223146 * A006409 A173813 A249643

Adjacent sequences:  A239762 A239763 A239764 * A239766 A239767 A239768

KEYWORD

nonn,more

AUTHOR

Chad Brewbaker, Mar 26 2014

EXTENSIONS

a(6)-a(7) from Giovanni Resta, Mar 28 2014

STATUS

approved

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Last modified December 9 09:21 EST 2019. Contains 329877 sequences. (Running on oeis4.)