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 A183805 1/16 the number of (n+1) X 4 binary arrays with no 2 X 2 subblock being a reflection across the shared element pair of any horizontal or vertical neighbor. 1
 9, 55, 322, 1953, 11619, 70044, 418925, 2518389, 15091626, 90619253, 543451183, 3261698460, 19566441353, 117412757177, 704423288546, 4226740369841, 25359685459275, 152160965127516, 912955035168789, 5477770757446957 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 3 of A183811. LINKS R. H. Hardin, Table of n, a(n) for n = 1..200 FORMULA Empirical: a(n) = 6*a(n-1) + 12*a(n-2) - 83*a(n-3) + 56*a(n-4) + 60*a(n-5). Empirical g.f.: x*(9 + x - 116*x^2 + 108*x^3 + 98*x^4) / ((1 - 2*x)*(1 - 6*x)*(1 + 2*x - 8*x^2 - 5*x^3)). - Colin Barker, Apr 04 2018 EXAMPLE Some solutions with upper left block zero for 3 X 4: 0 0 1 1 0 0 0 1 0 0 0 0 0 0 1 1 0 0 0 1 0 0 0 0 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 1 1 0 1 1 0 0 1 1 1 0 0 1 0 1 1 0 1 0 CROSSREFS Cf. A183811. Sequence in context: A244650 A097790 A356339 * A037578 A096191 A281454 Adjacent sequences: A183802 A183803 A183804 * A183806 A183807 A183808 KEYWORD nonn AUTHOR R. H. Hardin, Jan 07 2011 STATUS approved

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Last modified December 2 15:00 EST 2022. Contains 358510 sequences. (Running on oeis4.)