A145773 Number of n X n binary arrays with all ones connected only either two adjacent vertically or two adjacent horizontally.

1, 1, 5, 25, 314, 7358, 349511, 32855368, 6141909014, 2284689480141, 1689669248970784, 2485350221377308028, 7269523179423750332937, 42286820404292801713317670, 489171492515135237008883532896, 11253368362763343319841968035523559, 514834001847660368120286449303218684955

Offset

0,3

Links

Table of n, a(n) for n=0..16.

Example

Maximal 5 X 5 example
.1.1.0.0.1
.0.0.0.0.1
.1.0.1.1.0
.1.0.0.0.1
.0.1.1.0.1

Crossrefs

Main diagonal of A196436.

Cf. A386664.

Sequence in context: A185063 A165656 A370336 * A197195 A358545 A285602

Adjacent sequences: A145770 A145771 A145772 * A145774 A145775 A145776

Keyword

nonn

Author

R. H. Hardin, Oct 18 2008

Extensions

a(15)-a(16) from Alois P. Heinz, Jan 19 2026

Status

approved