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 A268880 Number of n X n binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once. 1
 0, 5, 84, 4133, 317966, 55491832, 19876401224, 15564645769042, 26617222097087230, 99905925686618815012, 832547140418699137884096, 15355865014207234684746438192, 632296902429868672596327438625296 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Diagonal of A268886. LINKS R. H. Hardin, Table of n, a(n) for n = 1..26 EXAMPLE Some solutions for n=4 ..1..1..0..0. .0..1..0..1. .0..0..0..1. .0..0..1..0. .0..0..0..0 ..0..0..0..0. .0..1..0..0. .0..0..1..0. .1..0..1..0. .0..1..0..1 ..0..0..0..0. .1..0..0..1. .1..0..1..0. .0..0..0..0. .0..1..0..0 ..0..0..0..1. .0..0..0..1. .1..0..0..1. .1..0..1..1. .1..0..1..0 CROSSREFS Cf. A268886. Sequence in context: A111911 A156720 A288163 * A048143 A216420 A137083 Adjacent sequences:  A268877 A268878 A268879 * A268881 A268882 A268883 KEYWORD nonn AUTHOR R. H. Hardin, Feb 15 2016 STATUS approved

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Last modified September 27 03:05 EDT 2021. Contains 347673 sequences. (Running on oeis4.)