login
A156433
Number of n X n arrays of squares of integers, symmetric under 90 degree rotation, with all rows summing to 3.
0
1, 2, 0, 0, 42, 276, 0, 0, 20340, 216680, 0, 0, 30693320, 449345680, 0, 0, 105796267920, 1972495637280, 0, 0, 696951215563680, 15784392403940160, 0, 0, 7817495632183997760, 208339434598512497280, 0, 0
OFFSET
3,2
CROSSREFS
Sequence in context: A013369 A013416 A365973 * A169771 A365982 A326779
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 09 2009
STATUS
approved