

A201535


Number of nX4 0..2 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor


1



6, 69, 633, 7799, 91425, 983981, 9526987, 82847704, 652848538, 4712696751, 31480011434, 196280028176, 1150650039753, 6380377582098, 33631853768986, 169225758487160, 815686475352515, 3777731764480697, 16854911299206527
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OFFSET

1,1


COMMENTS

Column 4 of A201539


LINKS

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


FORMULA

Empirical: a(n) is a polynomial of degree 80 for n>43


EXAMPLE

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


CROSSREFS

Sequence in context: A183438 A296016 A288719 * A198699 A258792 A214694
Adjacent sequences: A201532 A201533 A201534 * A201536 A201537 A201538


KEYWORD

nonn


AUTHOR

R. H. Hardin Dec 02 2011


STATUS

approved



