A205191 Number of (n+1) X 7 0..1 arrays with the number of clockwise edge increases in every 2 X 2 subblock differing from each horizontal or vertical neighbor.
216, 272, 384, 576, 896, 1408, 2048, 2944, 4224, 6144, 8960, 13184, 19328, 28416, 41600, 61056, 89344, 131072, 191872, 281472, 412160, 604544, 885376, 1298432, 1901824, 2788736, 4085120, 5989632, 8774784, 12864640, 18848000, 27631104
Offset: 1
Keywords
Examples
Some solutions for n=4: ..0..0..0..1..1..1..0....1..0..0..1..0..1..1....0..0..1..1..0..0..1 ..1..0..0..1..1..0..1....1..0..0..0..1..1..1....0..0..1..1..0..0..1 ..0..1..1..0..0..1..1....0..1..0..0..1..1..0....0..1..0..0..1..1..0 ..0..1..1..0..0..1..1....0..0..1..1..0..0..1....1..0..0..0..1..1..1 ..1..0..0..1..1..0..0....0..0..1..1..0..0..1....0..0..0..1..0..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A205193.
Formula
Empirical: a(n) = a(n-1) +a(n-2) -a(n-3) +a(n-4) -a(n-5) +a(n-6) for n>10.
Empirical g.f.: 8*x*(27 + 7*x - 13*x^2 + 17*x^3 - x^4 + 33*x^5 - x^6 - 10*x^7 - 8*x^8 - 8*x^9) / ((1 - x^2 + x^3)*(1 - x - x^3)). - Colin Barker, Jun 11 2018
Comments