A145764 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only either three adjacent vertically or three adjacent horizontally.

1, 1, 5, 5, 24, 73, 566, 2483, 32841, 234437, 5307036, 61459976, 2279718182, 44700555075, 2739362168120, 88170556642974, 8988213154883058

Offset

1,3

Links

Table of n, a(n) for n=1..17.

Crossrefs

Sequence in context: A090936 A366443 A262117 * A165826 A256693 A255458

Adjacent sequences: A145761 A145762 A145763 * A145765 A145766 A145767

Keyword

nonn

Author

R. H. Hardin, Oct 17 2008

Status

approved