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A239837 Number of ordered pairs of permutation functions on n elements satisfying f(f(x)) = g(f(g(x))). 2
1, 1, 2, 12, 96, 600, 6480, 85680, 1048320, 16692480, 315705600, 5468601600, 117834393600, 2951607859200, 68958028339200, 1856897602560000, 58228124258304000, 1721171464556544000, 56379302852640768000, 2111880588197732352000, 76033053559536353280000 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
Hiroaki Yamanouchi, Table of n, a(n) for n = 0..60
CROSSREFS
Cf. A000012, A000085, A000142, A088311, A053529, A001044.
Sequence in context: A321057 A366334 A247075 * A239838 A306258 A052691
Adjacent sequences: A239834 A239835 A239836 * A239838 A239839 A239840
KEYWORD
nonn
AUTHOR
Chad Brewbaker, Mar 27 2014
EXTENSIONS
a(8)-a(9) from Giovanni Resta, Mar 27 2014
a(10)-a(13) from Paul Boddington, Feb 23 2015
a(14)-a(20) from Hiroaki Yamanouchi, Mar 12 2015
STATUS
approved

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Last modified June 5 22:26 EDT 2024. Contains 373110 sequences. (Running on oeis4.)