A145758 Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only either three adjacent vertically or three adjacent horizontally.

1, 1, 7, 3, 46, 11, 1486, 401, 133777, 19881, 31874678, 3357350, 19385116046, 1369262857, 34450358764096, 1726253429208, 166321294438234974, 5602768757076743, 2202194423758663223078, 51308572928072165575

Offset

1,3

Links

Table of n, a(n) for n=1..20.

Crossrefs

Sequence in context: A271815 A194778 A272010 * A038269 A176328 A248279

Adjacent sequences: A145755 A145756 A145757 * A145759 A145760 A145761

Keyword

nonn

Author

R. H. Hardin, Oct 17 2008

Status

approved