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!)
A004206 Number of permutations of length n with spread 2.
(Formerly M2381)
1
3, 4, 25, 108, 735, 5248, 40824, 362000, 3628185, 39045888, 478988081, 6227101888, 87146087625, 1314459353088, 20922788404479, 355737629952000, 6402373698206889, 121479069952000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,1

REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=3..20.

R. L. Graham and D. H. Lehmer, On the Permanent of Schur's Matrix, Jour. Australian Math. Soc. 21 no. 4 (series A) (1976), 487-497.

CROSSREFS

Sequence in context: A212696 A192346 A055348 * A302397 A151372 A258103

Adjacent sequences:  A004203 A004204 A004205 * A004207 A004208 A004209

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), May 17 2007

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 June 2 14:21 EDT 2020. Contains 334787 sequences. (Running on oeis4.)