login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A018931 The number of permutations of n cards in which 2 is the first card hit and 3 the next hit after 2. 1
0, 1, 2, 12, 72, 480, 3600, 30240 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,3

COMMENTS

From the game of Mousetrap.

REFERENCES

Mundfrom, Daniel J.; A problem in permutations: the game of `Mousetrap'. European J. Combin. 15 (1994), no. 6, 555-560.

LINKS

Table of n, a(n) for n=3..10.

D. J. Mundform, A problem of permutations: the Game of 'Moustrap', Eur. J. Combinat. 15 (1994) 555-560, Table 1.

FORMULA

a(n) = A062119(n-3), n>4. - R. J. Mathar, Oct 02 2008

CROSSREFS

Cf. A002468.

Sequence in context: A322276 A279154 A167747 * A062119 A181966 A052556

Adjacent sequences:  A018928 A018929 A018930 * A018932 A018933 A018934

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Changed offset to 3. Provided more precise definition. - R. J. Mathar, Oct 02 2008

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 13 11:56 EDT 2021. Contains 342936 sequences. (Running on oeis4.)