|
| |
|
|
A054343
|
|
Number of nonnegative integer 3 X 3 matrices with sum of elements equal to n, under action of dihedral group of the square D_4.
|
|
2
| |
|
|
1, 3, 11, 31, 84, 198, 440, 904, 1766, 3266, 5802, 9906, 16384, 26284, 41104, 62752, 93831, 137589, 198309, 281249, 393148, 542154, 738480, 994320, 1324668, 1747220, 2283396, 2958228, 3801600, 4848120, 6138624, 7720032, 9647133
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
FORMULA
| G.f.: (2*x^6+2*x^5+x^4+4*x^2-2*x+1)/((1-x^4)^2*(1-x^2)^2*(1-x)^5).
|
|
|
EXAMPLE
| There are 11 nonisomorphic nonnegative integer 3 X 3 matrices with sum of elements equal to 2, under action of D_4:
[0 0 0] [0 0 0] [0 0 0] [0 0 0] [0 0 0] [0 0 0] [0 0 0] [0 0 1] [0 0 0] [0 0 0] [0 0 0]
[0 0 0] [0 0 0] [0 0 1] [0 0 1] [0 1 0] [0 1 0] [1 0 1] [0 0 0] [0 0 0] [0 0 0] [0 2 0]
[0 1 1] [1 0 1] [0 1 0] [1 0 0] [0 0 1] [0 1 0] [0 0 0] [1 0 0] [0 0 2] [0 2 0] [0 0 0].
|
|
|
CROSSREFS
| Cf. A005232, A052365.
Sequence in context: A190590 A087323 A034543 * A108898 A119901 A106934
Adjacent sequences: A054340 A054341 A054342 * A054344 A054345 A054346
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| Vladeta Jovovic (vladeta(AT)eunet.rs), May 05 2000
|
| |
|
|
