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A239762 Number of pairs of functions (f,g) from a set of n elements into itself satisfying f(f(g(x))) = g(f(x)). 0
1, 1, 10, 159, 3568, 106545, 4062336, 192754009 (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: A239761 A245916 A245914 * A087961 A116041 A284110

Adjacent sequences:  A239759 A239760 A239761 * A239763 A239764 A239765

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 5 03:59 EST 2021. Contains 349530 sequences. (Running on oeis4.)