

A199903


Number of 2..2 arrays x(0..n1) of n elements with zero sum, and adjacent elements not equal modulo three (with 1 modulo 3 = 2)


1



1, 4, 12, 24, 82, 232, 654, 2044, 6096, 18564, 57500, 177032, 550098, 1715956, 5359158, 16799508, 52760640, 165976252, 523094304, 1650781728, 5216112586, 16501009804, 52252555938, 165618780196, 525388548976, 1667965025692
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OFFSET

1,2


COMMENTS

Column 2 of A199909


LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200


EXAMPLE

Some solutions for n=6
..1....0....0....1....1....1....1....1...1...1...1....0....0...2....1...1
..2....1...2....2....0....0....0...1....0....0...2...1...2....2....2....0
.2....0....2....0....2...1...1...2....1....1....0....0...1....0...2....1
..0....1....1...1...2...2...2....2....0....2....1....2....0...1...1...1
.1....0...1....0...1....0....2...2...1...2....0....0....2....0...2....0
..0...2....0...2....0....2....0....2....1....0....2...1....1....1....2....1


CROSSREFS

Sequence in context: A282512 A025543 A064354 * A218034 A140813 A073841
Adjacent sequences: A199900 A199901 A199902 * A199904 A199905 A199906


KEYWORD

nonn


AUTHOR

R. H. Hardin Nov 11 2011


STATUS

approved



