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R. H. Hardin, <a href="/A268909/b268909.txt">Table of n, a(n) for n = 1..210</a>

allocated for R. H. Hardin

Number of 6Xn 0..2 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

0, 33792, 715392, 14644152, 282550680, 5344944120, 99308573208, 1821165633864, 33033242938536, 593761996675728, 10591066349377632, 187684309946743128, 3307315733915348808, 57997191529735867080, 1012715407159459735536

1,2

Row 6 of A268904.

Empirical: a(n) = 60*a(n-1) -1466*a(n-2) +19056*a(n-3) -143515*a(n-4) +608478*a(n-5) -957350*a(n-6) -3924114*a(n-7) +27201539*a(n-8) -68079378*a(n-9) +46537423*a(n-10) +212613240*a(n-11) -785654632*a(n-12) +1389943104*a(n-13) -1544105168*a(n-14) +1125401088*a(n-15) -524553472*a(n-16) +142135296*a(n-17) -17040384*a(n-18) for n>26

Some solutions for n=2

..1..0. .0..0. .2..0. .0..1. .0..1. .1..1. .1..2. .0..1. .0..2. .1..0

..1..0. .1..2. .1..2. .0..2. .0..0. .2..2. .2..1. .0..2. .2..2. .1..0

..1..1. .1..0. .1..2. .2..1. .1..0. .1..2. .2..1. .2..2. .1..2. .0..1

..0..0. .1..0. .1..0. .2..1. .1..2. .2..2. .2..1. .2..2. .2..1. .2..1

..1..2. .1..2. .1..2. .2..2. .0..1. .2..1. .2..2. .2..1. .0..1. .1..0

..1..2. .1..1. .1..2. .2..1. .0..1. .0..0. .0..0. .2..2. .2..2. .0..0

Cf. A268904.

allocated

nonn

R. H. Hardin, Feb 15 2016

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