A202131 - OEIS

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A202131

Number of zero-sum nX2 -3..3 arrays with every element equal to at least one horizontal or vertical neighbor

1, 13, 123, 1205, 12287, 135179, 1493247, 16814401, 192346557, 2225951035, 26017190841, 306761764259, 3644115496927, 43571997337907, 523947428428811, 6331638407455241, 76845558853198515, 936178097032511349

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Column 2 of A202134

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..73

EXAMPLE

Some solutions for n=5

..2..2....2..2...-3.-3....2..1....1..1...-2.-2....1..1....2.-3...-3.-1....1..2

.-1.-1....1.-2....3..3....2..1....3..0....2.-3...-3.-3....2.-3...-3.-1....1..2

..2..2....1.-2....2..2....0..0....3..0....2.-3....1..2...-1.-1....1..2....0..0