A190606 - OEIS

A190606

Number of (n+2)X(n+2) symmetric binary matrices without the pattern 1 0 1 diagonally, vertically or horizontally

39, 240, 2271, 35661, 836514, 27940563, 1374170474, 102369944843, 11464683896495, 1905358977494462, 469934471799881606, 172863979596481949179, 94947989820190085424440

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..14

EXAMPLE

Some solutions for 4X4

..0..0..1..1....0..0..1..1....0..0..0..1....0..0..1..0....0..0..1..0

..0..0..1..1....0..1..1..1....0..0..1..0....0..0..1..0....0..0..1..1

..1..1..0..0....1..1..1..1....0..1..0..0....1..1..1..0....1..1..1..1

..1..1..0..0....1..1..1..0....1..0..0..1....0..0..0..1....0..1..1..0

CROSSREFS

Sequence in context: A211503 A266104 A190538 * A101627 A229639 A070146

Adjacent sequences: A190603 A190604 A190605 * A190607 A190608 A190609

KEYWORD

nonn

AUTHOR

R. H. Hardin May 13 2011

STATUS

approved