A237160 Number of (n+1) X (1+1) 0..2 arrays with the maximum plus the minimum minus the upper median minus the lower median of every 2 X 2 subblock equal.

81, 245, 777, 2597, 8961, 31837, 115561, 427093, 1600465, 6064925, 23183481, 89239333, 345404641, 1342911981, 5240253833, 20510674037, 80485531761, 316523691581, 1247135002521, 4921936192325, 19452979579137, 76982463799693

Offset

1,1

Links

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

Formula

Empirical: a(n) = 7*a(n-1) + 2*a(n-2) - 92*a(n-3) + 80*a(n-4) + 376*a(n-5) - 360*a(n-6) - 600*a(n-7) + 400*a(n-8) + 320*a(n-9).

Empirical g.f.: x*(81 - 322*x - 1100*x^2 + 4120*x^3 + 5288*x^4 - 14656*x^5 - 11416*x^6 + 15792*x^7 + 9664*x^8) / ((1 - 4*x)*(1 - 2*x^2)*(1 - 3*x - 2*x^2)*(1 - 10*x^2 + 20*x^4)). - Colin Barker, Oct 21 2018

Example

Some solutions for n=5:
..0..1....2..1....2..1....2..1....1..0....1..0....1..2....2..2....0..2....1..1
..2..1....1..0....2..1....1..0....1..2....1..2....1..2....1..1....0..2....2..0
..0..1....1..2....0..1....0..1....0..1....0..1....1..0....1..1....0..2....0..2
..1..2....0..1....1..2....1..2....1..2....2..1....2..1....2..2....0..2....0..2
..1..0....0..1....0..1....1..0....2..1....2..1....0..1....0..0....2..0....1..1
..1..0....1..0....0..1....2..1....0..1....1..0....1..2....1..1....2..0....1..1

Crossrefs

Column 1 of A237167.

Sequence in context: A237167 A236893 A044986 * A236886 A206142 A225027

Adjacent sequences: A237157 A237158 A237159 * A237161 A237162 A237163

Keyword

nonn

Author

R. H. Hardin, Feb 04 2014

Status

approved