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A047865 Number of derangements of n where minimal cycle size is 4. 3
1, 0, 0, 0, 6, 24, 120, 720, 6300, 58464, 586656, 6384960, 76471560, 994831200, 13939507296, 209097854784, 3345235180560, 56866395720960, 1023601917024000, 19448577603454464, 388972171805410656, 8168409582839579520 (list; graph; refs; listen; history; internal format)
OFFSET

0,5

REFERENCES

H. S. Wilf, Generatingfunctionology, Academic Press, NY, 1990, p. 147, Eq. 5.2.9 (q=3).

LINKS

H. S. Wilf, Generatingfunctionology, 2nd edn., Academic Press, NY, 1994, p. 176, Eq. 5.2.9 (q=3).

MAPLE

ZL3:=[S, {S=Set(Cycle(Z, card>3))}, labeled] :seq(count(ZL3, size=n), n=0..21); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Sep 26 2007

CROSSREFS

Cf. A038205, A000166.

Sequence in context: A026982 A051197 A050212 * A060249 A052557 A188232

Adjacent sequences:  A047862 A047863 A047864 * A047866 A047867 A047868

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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Last modified February 16 17:11 EST 2012. Contains 205938 sequences.