A251126 Number of (n+1) X (6+1) 0..1 arrays with no 2 X 2 subblock having the sum of its diagonal elements greater than the maximum of its antidiagonal elements.

212, 315, 430, 612, 854, 1214, 1743, 2550, 3795, 5747, 8835, 13757, 21640, 34309, 54716, 87638, 140804, 226720, 365621, 590248, 953577, 1541325, 2492185, 4030567, 6519574, 10546719, 17062618, 27605400, 44663810, 72264722, 116923755

Offset

1,1

Links

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

Formula

Empirical: a(n) = 4*a(n-1) - 5*a(n-2) + a(n-3) + 2*a(n-4) - a(n-5) for n>6.

Empirical g.f.: x*(212 - 533*x + 230*x^2 + 255*x^3 - 183*x^4 + 10*x^5) / ((1 - x)^3*(1 - x - x^2)). - Colin Barker, Nov 26 2018

Example

Some solutions for n=4:
..0..0..0..1..0..1..1....0..0..1..0..1..0..1....0..0..0..0..1..0..1
..0..0..0..1..0..0..0....0..0..1..0..1..0..1....0..0..0..0..1..0..1
..0..0..0..1..0..0..0....0..0..1..0..1..0..0....0..0..0..0..1..0..1
..1..0..0..1..0..0..0....0..0..1..0..1..0..0....0..0..0..0..1..0..1
..1..0..0..1..0..0..0....1..1..1..0..1..0..0....1..1..1..1..1..0..0

Crossrefs

Column 6 of A251128.

Sequence in context: A133651 A093807 A088642 * A078211 A158794 A204364

Adjacent sequences: A251123 A251124 A251125 * A251127 A251128 A251129

Keyword

nonn

Author

R. H. Hardin, Nov 30 2014

Status

approved