A145790 Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only either four adjacent vertically or four adjacent horizontally.

1, 1, 1, 9, 11, 36, 65, 515, 2420, 18065, 172108, 1981958, 24609296, 431265080, 7420809238, 183434050306, 4983211868325, 173511007323269, 7989094384834315, 376330135051842303, 28830157229045747299, 1923394214566012353119

Offset

1,4

Links

Table of n, a(n) for n=1..22.

Crossrefs

Sequence in context: A130730 A153697 A129399 * A345109 A143465 A201999

Adjacent sequences: A145787 A145788 A145789 * A145791 A145792 A145793

Keyword

nonn

Author

R. H. Hardin, Oct 19 2008

Status

approved