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A255525
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1/n! times the number of ordered pairs of permutation functions f,g on n elements where f(g(g(x))) = g(f(f(x))).
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0
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1, 1, 1, 1, 2, 3, 4, 6, 9, 13, 17, 27, 31, 42, 57, 83, 104
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OFFSET
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0,5
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COMMENTS
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The fact that A239836(n) is a multiple of n! follows from a general result in group theory due to Solomon.
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LINKS
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FORMULA
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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