

A237550


Number of (n+1) X (1+1) 0..2 arrays with the maximum minus the upper median of every 2 X 2 subblock differing from its horizontal and vertical neighbors by exactly one.


1



81, 312, 1240, 4752, 19128, 72736, 290112, 1110080, 4459296, 16979328, 67827328, 259259648, 1040224128, 3964054016, 15850143744, 60545315840, 242745766400, 925519968256, 3702814799872, 14138549342208, 56660164196352
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OFFSET

1,1


LINKS

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


FORMULA

Empirical: a(n) = 192*a(n4) + 608*a(n6) + 400*a(n8) for n>9.
Empirical g.f.: x*(81 + 312*x + 1240*x^2 + 4752*x^3 + 3576*x^4 + 12832*x^5 + 2784*x^6 + 8000*x^7 + 400*x^8) / (1  192*x^4  608*x^6  400*x^8).  Colin Barker, Oct 22 2018


EXAMPLE

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


CROSSREFS

Column 1 of A237557.
Sequence in context: A237703 A237696 A237557 * A237567 A237560 A237332
Adjacent sequences: A237547 A237548 A237549 * A237551 A237552 A237553


KEYWORD

nonn


AUTHOR

R. H. Hardin, Feb 09 2014


STATUS

approved



