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Search: id:A070946
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| A070946 |
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Number of permutations on n letters that have only cycles of length 5 or less. |
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+0
2
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| 1, 1, 2, 6, 24, 120, 600, 3480, 22800, 164880, 1285920, 10516320, 92931840, 877374720, 8762014080, 91819440000, 1005716908800, 11584953158400, 139521689740800, 1748830512960000, 22750446292531200, 306931140411955200
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OFFSET
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0,3
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FORMULA
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E.g.f.: exp(x+1/2*x^2+1/3*x^3+1/4*x^4+1/5*x^5).
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MAPLE
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with (combstruct):a:=proc(m) [ZL, {ZL=Set(Cycle(Z, m>=card))}, labeled]; end: A:=a(5):seq(count(A, size=n), n=0..21); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 11 2008
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CROSSREFS
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Cf. A057693.
Sequence in context: A048631 A062348 A072856 this_sequence A060726 A152332 A152349
Adjacent sequences: A070943 A070944 A070945 this_sequence A070947 A070948 A070949
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com) and Sharon Sela, May 18 2002
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