A147142 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1000-1100-0110-0011 pattern in any orientation.

1, 1, 1, 3, 7, 17, 39, 127, 681, 3913, 21369, 147701, 1344439, 15252227, 199338371, 3018576265, 55990200331, 1283966558111, 35424143775231

Offset

1,4

Links

Table of n, a(n) for n=1..19.

Example

Maximal 8 X 8 example
.0.0.0.0.1.1.0.0
.0.0.0.0.0.1.1.0
.0.0.0.0.0.0.1.1
.0.0.0.0.1.1.0.1
.1.0.0.1.0.1.1.0
.1.1.0.1.1.0.1.1
.0.1.1.0.1.1.0.1
.0.0.1.1.0.1.1.0

Crossrefs

Sequence in context: A229514 A077927 A005197 * A298371 A367396 A106472

Adjacent sequences: A147139 A147140 A147141 * A147143 A147144 A147145

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved