|
%I #11 May 29 2014 12:55:55
%S 1,0,1,0,1,2,0,0,4,4,0,0,0,16,12,0,0,0,4,72,36,0,0,0,0,36,324,144,0,0,
%T 0,0,0,324,1728,576,0,0,0,0,0,36,2592,9216,2880,0,0,0,0,0,0,576,20736,
%U 57600,14400,0,0,0,0,0,0,0,9216,172800,360000,86400,0,0,0,0,0,0,0,576
%N T(n,k) = [n/2]!*[(n+1)/2]!*C([n/2],k-1)*C([(n+1)/2],k-1).
%C T(n,k)=Number of permutations of n elements with 2k-2 odd displacements
%C Table starts:
%C .........1...........0............0............0............0............0
%C .........1...........1............0............0............0............0
%C .........2...........4............0............0............0............0
%C .........4..........16............4............0............0............0
%C ........12..........72...........36............0............0............0
%C ........36.........324..........324...........36............0............0
%C .......144........1728.........2592..........576............0............0
%C .......576........9216........20736.........9216..........576............0
%C ......2880.......57600.......172800.......115200........14400............0
%C .....14400......360000......1440000......1440000.......360000........14400
%C .....86400.....2592000.....12960000.....17280000......6480000.......518400
%C ....518400....18662400....116640000....207360000....116640000.....18662400
%C ...3628800...152409600...1143072000...2540160000...1905120000....457228800
%C ..25401600..1244678400..11202105600..31116960000..31116960000..11202105600
%C .203212800.11379916800.119489126400.398297088000.497871360000.238978252800
%H R. H. Hardin, <a href="/A226288/b226288.txt">Table of n, a(n) for n = 1..10000</a>
%Y Column 1 is A010551.
%Y Columns 2-7 are: A226282-A226287.
%Y Cf. A145891 (another version as irregular triangle)
%K nonn,tabl
%O 1,6
%A _R. H. Hardin_, connection of formula with combinatoric problem via _N. J. A. Sloane_ in the Sequence Fans Mailing List, Jun 02 2013
|
