A145761 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only either three adjacent vertically or three adjacent horizontally.

1, 1, 1, 1, 2, 3, 6, 9, 29, 71, 252, 692, 3368, 13077, 79134, 377418, 2968590, 18765157, 189063004, 1516592933, 19680440925, 204860397699, 3422227126547, 45691959144342, 982062906171101, 16911337817136038, 468085274414196900

Offset

1,5

Links

Table of n, a(n) for n=1..27.

Crossrefs

Sequence in context: A349148 A002076 A286435 * A071714 A077753 A353122

Adjacent sequences: A145758 A145759 A145760 * A145762 A145763 A145764

Keyword

nonn

Author

R. H. Hardin, Oct 17 2008

Status

approved