A141514 Number of n X n binary matrices, symmetric under 180 degree rotation, with no more than 3 ones in any 2 X 2 subblock.

1, 2, 3, 29, 176, 5621, 122557, 14694960, 1181467639, 516777127561, 152237306877120, 244601068560037129, 264412894413046723521, 1557984885076079288613088, 6177872087977594821120364739

Offset

0,2

Links

R. H. Hardin, Table of n, a(n) for n = 0..20

Crossrefs

Sequence in context: A144953 A132282 A064893 * A078727 A350868 A270550

Adjacent sequences: A141511 A141512 A141513 * A141515 A141516 A141517

Keyword

nonn

Author

R. H. Hardin, Aug 10 2008

Status

approved