A190416 Number of (n+2)X(n+2) symmetric binary matrices without the pattern 1 1 1 antidiagonally

48, 432, 7776, 279936, 18475776, 2235568896, 491825157120, 196730062848000, 145580246507520000, 199299357468794880000, 501437183391487918080000, 2318645536002240133201920000, 19708487056019041132216320000000

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..58

Example

Some solutions for n=2
..0..1..1..1....1..1..0..0....0..0..0..0....1..1..1..0....1..1..0..1
..1..0..0..0....1..0..1..1....0..0..0..0....1..0..1..0....1..0..0..1
..1..0..0..0....0..1..0..0....0..0..0..0....1..1..0..1....0..0..0..0
..1..0..0..0....0..1..0..0....0..0..0..0....0..0..1..1....1..1..0..1

Crossrefs

Sequence in context: A249293 A347168 A281374 * A231342 A192828 A259851

Adjacent sequences: A190413 A190414 A190415 * A190417 A190418 A190419

Keyword

nonn

Author

R. H. Hardin May 10 2011

Status

approved