A234155 Number of (n+1) X (2+1) 0..3 arrays with every 2 X 2 subblock having the absolute values of all six edge and diagonal differences no larger than 1.

226, 2210, 21428, 208530, 2031286, 19801468, 193116778, 1883946390, 18382182848, 179381051374, 1750606214186, 17085236474192, 166750308889438, 1627498698611826, 15884734670855980, 155039607250962794

Offset

1,1

Links

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

Formula

Empirical: a(n) = 16*a(n-1) - 59*a(n-2) - 31*a(n-3) + 118*a(n-4) + 35*a(n-5) - 10*a(n-6).

Empirical g.f.: 2*x*(113 - 703*x - 299*x^2 + 1539*x^3 + 450*x^4 - 130*x^5) / (1 - 16*x + 59*x^2 + 31*x^3 - 118*x^4 - 35*x^5 + 10*x^6). - Colin Barker, Oct 13 2018

Example

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

Crossrefs

Column 2 of A234161.

Sequence in context: A156814 A251605 A233943 * A251402 A251395 A251507

Adjacent sequences: A234152 A234153 A234154 * A234156 A234157 A234158

Keyword

nonn

Author

R. H. Hardin, Dec 20 2013

Status

approved