

A215953


Number of horizontal, vertical and diagonal neighbor colorings of the even squares of an n X 2 array with new integer colors introduced in row major order.


2



1, 1, 2, 4, 12, 34, 136, 500, 2440, 10900, 61912, 322768, 2075312, 12297768, 87852160, 580849872, 4548247264, 33093252880, 281121815712, 2227152575552, 20358402201792, 174131286983712, 1701534399324544, 15604440074084672
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OFFSET

1,3


COMMENTS

Column 2 of A215959.


LINKS

R. H. Hardin, Table of n, a(n) for n = 1..122


EXAMPLE

Some solutions for n=5
..0..x....0..x....0..x....0..x....0..x....0..x....0..x....0..x....0..x....0..x
..x..1....x..1....x..1....x..1....x..1....x..1....x..1....x..1....x..1....x..1
..1..x....1..x....2..x....2..x....2..x....1..x....2..x....1..x....2..x....1..x
..x..0....x..2....x..3....x..3....x..0....x..0....x..0....x..2....x..3....x..2
..0..x....0..x....1..x....0..x....1..x....2..x....0..x....3..x....4..x....2..x


CROSSREFS

Sequence in context: A148203 A240904 A245310 * A209027 A069727 A148204
Adjacent sequences: A215950 A215951 A215952 * A215954 A215955 A215956


KEYWORD

nonn


AUTHOR

R. H. Hardin, Aug 28 2012


STATUS

approved



