A147087 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 10001-11111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 3, 5, 9, 15, 27, 43, 124, 355, 1029, 2971, 10017, 31249, 124044, 490643, 2352059, 10915093, 60936189, 323565841, 2097402227

Offset

1,9

Links

Table of n, a(n) for n=1..27.

Example

Maximal 9 X 9 example
.0.0.1.0.0.0.1.0.0
.0.0.1.1.1.1.1.0.0
.1.1.0.0.0.0.0.1.1
.0.1.0.0.0.0.0.1.0
.0.1.0.0.0.0.0.1.0
.0.1.0.0.0.0.0.1.0
.1.1.0.0.0.0.0.1.1
.0.0.1.1.1.1.1.0.0
.0.0.1.0.0.0.1.0.0

Crossrefs

Sequence in context: A018342 A029485 A291153 * A140190 A298352 A083658

Adjacent sequences: A147084 A147085 A147086 * A147088 A147089 A147090

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved