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 A304143 Number of nX2 0..1 arrays with every element unequal to 1, 2, 3 or 6 king-move adjacent elements, with upper left element zero. 4
 1, 7, 14, 33, 70, 157, 346, 769, 1710, 3813, 8514, 19049, 42678, 95757, 215114, 483793, 1089150, 2454197, 5534546, 12490169, 28205510, 63730653, 144073434, 325848609, 737262478, 1668717957, 3778162914, 8556569353, 19383222230, 43918469037 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Column 2 of A304149. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 2*a(n-1) +3*a(n-2) -2*a(n-3) -6*a(n-4) -4*a(n-5) for n>6. Empirical g.f: x -x^2*(-7+16*x^2+24*x^3+12*x^4) / ( (2*x-1) *(1+x) *(2*x^3+2*x^2+x-1) ). - R. J. Mathar, May 08 2018 EXAMPLE Some solutions for n=5 ..0..1. .0..1. .0..1. .0..0. .0..1. .0..1. .0..1. .0..1. .0..0. .0..1 ..1..1. .0..1. .0..1. .1..0. .1..1. .0..0. .1..1. .1..1. .1..1. .1..1 ..1..1. .1..0. .0..1. .1..1. .1..1. .1..0. .0..1. .0..0. .1..0. .1..0 ..0..1. .1..0. .1..0. .0..0. .0..0. .1..1. .0..0. .0..0. .0..0. .0..0 ..0..0. .1..0. .0..1. .0..1. .1..0. .0..1. .1..1. .1..0. .1..1. .1..0 CROSSREFS Cf. A304149. Sequence in context: A058530 A293359 A134384 * A055780 A161814 A333594 Adjacent sequences:  A304140 A304141 A304142 * A304144 A304145 A304146 KEYWORD nonn AUTHOR R. H. Hardin, May 07 2018 STATUS approved

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Last modified September 21 02:46 EDT 2020. Contains 337266 sequences. (Running on oeis4.)