A145774 Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only either two adjacent vertically or two adjacent horizontally.

1, 3, 5, 18, 124, 889, 9624, 117592, 3086899, 71342470, 3940302454, 162484045629, 19765145478158, 1482360209667114, 393627814809408705, 53489489176352337875, 30927278141339388397696, 7617052120730650394236371

Offset

1,2

Links

Table of n, a(n) for n=1..18.

Crossrefs

Sequence in context: A176749 A374649 A374917 * A348778 A270894 A272317

Adjacent sequences: A145771 A145772 A145773 * A145775 A145776 A145777

Keyword

nonn

Author

R. H. Hardin, Oct 18 2008

Status

approved