A234913 Number of (n+1) X (n+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 2, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

40, 360, 3684, 55492, 991144, 28854040, 911837036, 56108159524, 3092040129896

Offset

1,1

Links

Table of n, a(n) for n=1..9.

Example

Some solutions for n=4:
  3 2 1 2 1      0 3 2 1 0      1 4 3 0 1      2 1 2 1 0
  2 3 0 3 4      3 4 1 2 3      2 3 4 3 2      3 4 3 0 1
  3 2 1 2 1      0 3 2 1 0      1 0 3 0 1      2 1 2 1 4
  4 1 2 1 2      1 2 3 4 1      2 3 4 3 2      3 4 3 0 1
  1 0 3 4 3      2 1 4 3 2      1 4 3 0 1      4 3 4 3 2

Crossrefs

Diagonal of A234921.

Sequence in context: A247407 A251431 A285919 * A190312 A229532 A252180

Adjacent sequences: A234910 A234911 A234912 * A234914 A234915 A234916

Keyword

nonn

Author

R. H. Hardin, Jan 01 2014

Status

approved