A181254 Number of (n+2) X (n+2) binary matrices with every 3 X 3 block having exactly four 1's.

126, 746, 3190, 10818, 41374, 133850, 386406, 1297322, 3873790, 10724850

Offset

1,1

Links

Table of n, a(n) for n=1..10.

Example

Some solutions for 4 X 4:
  1 1 0 1     1 0 0 0     1 1 1 1     0 0 1 1     1 0 0 0
  1 0 0 0     0 0 1 0     0 0 1 0     1 0 0 1     1 0 1 1
  0 1 0 1     0 1 1 1     0 0 0 0     1 0 1 0     0 1 0 1
  1 0 1 1     1 0 0 0     1 1 1 1     0 0 1 1     1 0 0 0

Crossrefs

Diagonal of A181262.

Sequence in context: A186825 A186817 A107658 * A004008 A292981 A126170

Adjacent sequences: A181251 A181252 A181253 * A181255 A181256 A181257

Keyword

nonn

Author

R. H. Hardin, Oct 10 2010

Status

approved