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R. H. Hardin, <a href="/A266013/b266013.txt">Table of n, a(n) for n = 1..210</a>
allocated for R. H. Hardin
Number of 3Xn integer arrays with each element equal to the number of horizontal and antidiagonal neighbors equal to itself.
1, 2, 6, 4, 11, 18, 27, 43, 62, 112, 191, 310, 548, 883, 1467, 2535, 4210, 6993, 11848, 19780, 33042, 55676, 93207, 155834, 261837, 438753, 734590, 1232614, 2065881, 3460646, 5803604, 9727967, 16300819, 27328897, 45809212, 76772793, 128697166
1,2
Row 3 of A266012.
Empirical: a(n) = 3*a(n-3) +2*a(n-4) +2*a(n-5) +a(n-6) -2*a(n-7) -2*a(n-8) -3*a(n-9) +2*a(n-10) +2*a(n-11) +5*a(n-12) -a(n-15) for n>19
All solutions for n=4
..0..1..1..0....1..1..2..2....0..1..2..2....0..1..1..0
..0..2..2..1....0..2..2..0....1..2..2..0....0..2..2..0
..2..2..1..0....0..1..1..0....0..1..1..0....2..2..1..1
Cf. A266012.
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nonn
R. H. Hardin, Dec 20 2015
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allocated for R. H. Hardin
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