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 A183444 Number of n X 3 binary arrays with every 1 having exactly two king-move neighbors equal to 1. 2
 1, 9, 18, 30, 107, 265, 553, 1505, 3852, 8922, 22477, 56889, 137617, 340401, 851098, 2091618, 5160851, 12817517, 31655009, 78159377, 193558964, 478614470, 1182673261, 2925763109, 7235864705, 17887850273, 44237338898, 109401520982 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Column 3 of A183450. LINKS R. H. Hardin, Table of n, a(n) for n = 1..200 FORMULA Empirical: a(n) = 2*a(n-1) - a(n-2) + 8*a(n-3) - 7*a(n-4) + 2*a(n-5) - 2*a(n-6). Empirical g.f.: x*(1 + 7*x + x^2 - 5*x^3 - 2*x^5) / (1 - 2*x + x^2 - 8*x^3 + 7*x^4 - 2*x^5 + 2*x^6). - Colin Barker, Feb 27 2018 EXAMPLE Some solutions for 5 X 3: ..0..1..0....1..1..0....0..0..0....0..0..0....1..1..0....0..0..0....0..0..1 ..0..1..1....1..0..0....0..1..1....0..1..0....0..1..0....0..0..0....0..1..1 ..0..0..0....0..0..0....0..0..1....1..0..1....0..0..0....0..0..0....0..0..0 ..0..1..0....0..1..1....1..0..0....1..0..1....1..0..0....1..1..0....1..0..0 ..1..1..0....0..0..1....1..1..0....0..1..0....1..1..0....1..0..0....1..1..0 CROSSREFS Cf. A183450. Sequence in context: A044433 A161570 A140089 * A349417 A221533 A139591 Adjacent sequences: A183441 A183442 A183443 * A183445 A183446 A183447 KEYWORD nonn AUTHOR R. H. Hardin, Jan 04 2011 STATUS approved

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Last modified May 31 12:47 EDT 2023. Contains 363066 sequences. (Running on oeis4.)