A251125 Number of (n+1) X (5+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.

125, 193, 272, 401, 580, 854, 1268, 1912, 2921, 4520, 7069, 11153, 17717, 28291, 45350, 72899, 117418, 189392, 305786, 494050, 798599, 1291298, 2088427, 3378131, 5464835, 8841109, 14303948, 23142917, 37444576, 60585050, 98027024, 158609308

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*(125 - 307*x + 125*x^2 + 153*x^3 - 107*x^4 + 6*x^5) / ((1 - x)^3*(1 - x - x^2)). - Colin Barker, Nov 26 2018

Example

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

Crossrefs

Column 5 of A251128.

Sequence in context: A307386 A307515 A038513 * A252065 A252058 A038867

Adjacent sequences: A251122 A251123 A251124 * A251126 A251127 A251128

Keyword

nonn

Author

R. H. Hardin, Nov 30 2014

Status

approved