A226709 Number of n X n (-1,0,1) arrays of determinants of 2X2 subblocks of some (n+1)X(n+1) binary array

3, 71, 4671, 977939, 833949273, 2753775365011, 33686064493125445

Offset

1,1

Comments

Diagonal of A226717

Links

Table of n, a(n) for n=1..7.

Example

Some solutions for n=3
.-1..1..0...-1..0..0....1.-1..1....0..0..0....1.-1..1...-1.-1..0....0..1.-1
..1..0.-1....1..0..0...-1..0..1....0.-1..1....0.-1..0....1..0..0....0..0..1
.-1..0..1....1..0..1....1..0..0...-1..0..0....1..0..0...-1..0..0....1..0.-1

Crossrefs

Sequence in context: A111649 A349072 A272657 * A226844 A300540 A334124

Adjacent sequences: A226706 A226707 A226708 * A226710 A226711 A226712

Keyword

nonn

Author

R. H. Hardin Jun 15 2013

Status

approved