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