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A141503
Number of n X n binary matrices, symmetric under horizontal reflection, with no more than 2 ones in any 2 X 2 subblock.
1
1, 2, 3, 35, 85, 5529, 17421, 6468501, 30238457, 64377477751, 410142991045, 5056537169718019, 45365538098494225, 3235038360513128954137, 40254614759516328904462, 16631279103859270471807630795
OFFSET
0,2
LINKS
CROSSREFS
Sequence in context: A126910 A143887 A363499 * A199696 A234423 A165448
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 10 2008
STATUS
approved