A141509 Number of n X n binary matrices, symmetric under horizontal reflection, with no more than 3 ones in any 2 X 2 subblock.

1, 2, 3, 57, 128, 22077, 65205, 114142368, 468343535, 7969215344753, 44467930404864, 7479088292930771309, 57134805472751200753, 94492733598842569249024512, 986251920362343910672065291

Offset

0,2

Links

R. H. Hardin, Table of n, a(n) for n = 0..31

Crossrefs

Sequence in context: A179281 A000656 A116052 * A054313 A080052 A376675

Adjacent sequences: A141506 A141507 A141508 * A141510 A141511 A141512

Keyword

nonn

Author

R. H. Hardin, Aug 10 2008

Status

approved