A234486 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 2 (constant-stress 1 X 1 tilings).

3686, 13554, 49784, 183422, 677138, 2505400, 9288710, 34509914, 128461544, 479146446, 1790472578, 6703375016, 25141441190, 94466340970, 355552667288, 1340563920974, 5062700401010, 19151478723096, 72561523035974

Offset

1,1

Links

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

Formula

Empirical: a(n) = 16*a(n-1) -69*a(n-2) -186*a(n-3) +2233*a(n-4) -3610*a(n-5) -15789*a(n-6) +56088*a(n-7) +1729*a(n-8) -189898*a(n-9) +95019*a(n-10) +304674*a(n-11) -145486*a(n-12) -269396*a(n-13) +58980*a(n-14) +118584*a(n-15) +6480*a(n-16) -16992*a(n-17) -3456*a(n-18).

Example

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

Crossrefs

Column 4 of A234490.

Sequence in context: A252311 A263814 A179130 * A097500 A186198 A188155

Adjacent sequences: A234483 A234484 A234485 * A234487 A234488 A234489

Keyword

nonn

Author

R. H. Hardin, Dec 26 2013

Status

approved