A235285 Number of (n+1) X (4+1) 0..3 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).

136, 188, 248, 380, 544, 908, 1400, 2492, 4096, 7628, 13208, 25340, 45664, 89228, 165560, 326972, 619456, 1230668, 2366168, 4715900, 9162784, 18292748, 35811320, 71557052, 140857216, 281583308, 556527128, 1112792060, 2205927904, 4411331468

Offset

1,1

Comments

Column 4 of A235289

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +3*a(n-2) -15*a(n-3) +4*a(n-4) +18*a(n-5) -12*a(n-6).

Example

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

Crossrefs

Sequence in context: A157714 A165337 A256925 * A282794 A304606 A264951

Adjacent sequences: A235282 A235283 A235284 * A235286 A235287 A235288

Keyword

nonn

Author

R. H. Hardin, Jan 05 2014

Status

approved