A227640 Number of nX5 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X6 binary array having determinant equal to one, with rows and columns of the latter in nondecreasing lexicographic order

5, 44, 377, 3202, 25241, 179234, 1147095, 6679750, 35730988, 177168580, 820755334, 3576675995, 14747597428, 57825369396, 216544923909, 777378404391, 2683990390975, 8937664937815, 28776814807337, 89782546245762

Offset

1,1

Comments

Column 5 of A227641

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

R. H. Hardin, Empirical polynomial of degree 39

Formula

Empirical polynomial of degree 39 (see link above)

Example

Some solutions for n=4
..0..0..1..0..0....0..0..0..0..1....0..0..0..1..0....0..0..1..0..0
..0..1..0..0..0....0..1..0..0..0....0..0..0..0..0....0..1..0..0..1
..0..1..0..0..0....1..0..0..1..0....0..1..1..0..0....0..0..0..0..0
..1..0..1..0..1....0..0..0..0..0....1..0..1..1..0....0..1..0..0..0

Crossrefs

Sequence in context: A068311 A109984 A247776 * A096355 A371787 A222508

Adjacent sequences: A227637 A227638 A227639 * A227641 A227642 A227643

Keyword

nonn

Author

R. H. Hardin Jul 18 2013

Status

approved