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A247008
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Number of permutations on [n] admitting a tenth root.
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2
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1, 1, 1, 3, 12, 36, 126, 1386, 10248, 92232, 805896, 9862776, 107908416, 1428755328, 17338793472, 184781653056, 2707269941376, 58956779097216, 931404051946368, 18440063711701632, 369535355215842816, 8290691125502962176, 161390500012170164736
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OFFSET
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0,4
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LINKS
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MAPLE
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with(combinat): with(numtheory): with(padic):
b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
`if`(irem(j, mul(p^ordp(10, p), p=factorset(i)))=0, (i-1)!^j*
multinomial(n, n-i*j, i$j)/j!*b(n-i*j, i-1), 0), j=0..n/i)))
end:
a:= n-> b(n$2):
seq(a(n), n=0..25);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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