A127966 a(n) = number of 4-times (but not 5-times) reformable permutation of {1,...,n}.

2, 1, 1, 4, 14, 57

Offset

11,1

Comments

For n=16 we have the first example of a 5-reformed (but not 6-reformed) permutation: 1, 16, 12, 15, 6, 8, 14, 10, 9, 3, 4, 11, 13, 2, 7, 5 - Alberto M. Bersani (bersani(AT)dmmm.uniroma1.it), Feb 24 2008

References

A. M. Bersani, ``Reformed permutations in Mousetrap and its generalizations,'' Preprint Me.Mo.Mat. 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

Table of n, a(n) for n=11..16.

A. M. Bersani, On the game Mousetrap.

R. K. Guy and R. J. Nowakowski, Mousetrap, Amer. Math. Monthly, 101 (1994), 1007-1010.

Crossrefs

Cf. A007709, A007710, A007711, A007712, A055459, A067950.

Sequence in context: A166888 A083677 A075803 * A326570 A184880 A257859

Adjacent sequences: A127963 A127964 A127965 * A127967 A127968 A127969

Keyword

nonn,more

Author

Alberto M. Bersani (bersani(AT)dmmm.uniroma1.it), Feb 09 2007

Extensions

One more term from Alberto M. Bersani (bersani(AT)dmmm.uniroma1.it), Feb 24 2008

Status

approved