A235926 Number of (n+1) X (1+1) 0..3 arrays with the minimum plus the maximum unequal to the lower median plus the upper median in every 2 X 2 subblock.

168, 1788, 18992, 201976, 2146656, 22822704, 242602688, 2579082208, 27416534400, 291455295168, 3098309729024, 32936787698560, 350135170930176, 3722127720923904, 39568195366759424, 420631235622297088

Offset

1,1

Links

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

Formula

Empirical: a(n) = 82*a(n-2) + 320*a(n-3) + 144*a(n-4) - 448*a(n-5) + 64*a(n-6).

Empirical g.f.: 4*x*(42 + 447*x + 1304*x^2 + 400*x^3 - 1760*x^4 + 256*x^5) / (1 - 82*x^2 - 320*x^3 - 144*x^4 + 448*x^5 - 64*x^6). - Colin Barker, Oct 20 2018

Example

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

Crossrefs

Column 1 of A235932.

Sequence in context: A263121 A216107 A235932 * A279725 A234730 A234815

Adjacent sequences: A235923 A235924 A235925 * A235927 A235928 A235929

Keyword

nonn

Author

R. H. Hardin, Jan 17 2014

Status

approved