A235290 Number of (n+1) X (n+1) 0..3 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3 (constant-stress 1 X 1 tilings).

40, 232, 832, 3184, 9568, 32992, 97888, 333952, 1044640, 3677632

Offset

1,1

Comments

Diagonal of A235301.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +23*a(n-2) -92*a(n-3) -200*a(n-4) +800*a(n-5) +820*a(n-6) -3280*a(n-7) -1584*a(n-8) +6336*a(n-9) +1152*a(n-10) -4608*a(n-11) [see A235301 for assumption].

Example

Some solutions for n=5:
  2 0 0 0 0 0    3 3 3 3 2 3    1 3 2 3 3 3    3 1 3 1 3 1
  2 3 0 3 0 3    3 0 3 0 2 0    1 0 2 0 3 0    1 2 1 2 1 2
  3 1 1 1 1 1    1 1 1 1 0 1    1 3 2 3 3 3    3 1 3 1 3 1
  2 3 0 3 0 3    3 0 3 0 2 0    1 0 2 0 3 0    1 2 1 2 1 2
  2 0 0 0 0 0    3 3 3 3 2 3    1 3 2 3 3 3    2 0 2 0 2 0
  2 3 0 3 0 3    3 0 3 0 2 0    1 0 2 0 3 0    1 2 1 2 1 2

Crossrefs

Sequence in context: A072108 A218404 A235010 * A074360 A235885 A068790

Adjacent sequences: A235287 A235288 A235289 * A235291 A235292 A235293

Keyword

nonn

Author

R. H. Hardin, Jan 05 2014

Status

approved