A147409 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1001-1001-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 7, 13, 21, 31, 61, 147, 365, 1043, 3041, 10027, 33377, 115807, 406723, 1580475, 6700609

Offset

1,10

Links

Table of n, a(n) for n=1..25.

Example

Maximal 10 X 10 example
.0.0.0.1.0.0.1.0.0.0
.0.0.0.1.0.0.1.0.0.0
.0.0.0.1.1.1.1.0.0.0
.1.1.1.0.0.0.0.1.1.1
.0.0.1.0.0.0.0.1.0.0
.0.0.1.0.0.0.0.1.0.0
.1.1.1.0.0.0.0.1.1.1
.0.0.0.1.1.1.1.0.0.0
.0.0.0.1.0.0.1.0.0.0
.0.0.0.1.0.0.1.0.0.0

Crossrefs

Sequence in context: A098577 A004136 A335865 * A147342 A172310 A357370

Adjacent sequences: A147406 A147407 A147408 * A147410 A147411 A147412

Keyword

nonn

Author

R. H. Hardin

Status

approved