|
|
A067950
|
|
a(n) = number of 3-times (but not 4-times) reformable permutation of {1,...,n}.
|
|
5
|
|
|
1, 0, 1, 8, 31, 56, 219, 605, 2485, 9697, 40571
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
6,4
|
|
REFERENCES
|
A. M. Bersani, "Reformed permutations in Mousetrap and its generalizations", preprint MeMoMat n. 15/2005.
R. K. Guy and R. J. Nowakowski, ``Mousetrap,'' in D. Miklos, V.T. Sos and T. Szonyi, eds., Combinatorics, Paul Erdős is Eighty. Bolyai Society Math. Studies, Vol. 1, pp. 193-206, 1993.
|
|
LINKS
|
R. K. Guy and R. J. Nowakowski, Mousetrap Amer. Math. Monthly, 101 (1994), 1007-1010.
|
|
EXAMPLE
|
a(6)=1, 165342->132564->125346->136524.
|
|
CROSSREFS
|
|
|
KEYWORD
|
more,nonn
|
|
AUTHOR
|
Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Mar 06 2002
|
|
EXTENSIONS
|
2 more terms from Alberto M. Bersani (bersani(AT)dmmm.uniroma1.it), Feb 07 2007
One more term from Alberto M. Bersani (bersani(AT)dmmm.uniroma1.it), Feb 24 2008
|
|
STATUS
|
approved
|
|
|
|