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 A281210 Number of 6 X n 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. 1
 0, 420, 1120, 1588, 2602, 4248, 6838, 11010, 17840, 29120, 47838, 78978, 130842, 217250, 361188, 600860, 999718, 1663078, 2765630, 4596962, 7636856, 12679768, 21040526, 34894090, 57836514, 95810754, 158634028, 262516660, 434214550 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 4*a(n-1) - 4*a(n-2) - 2*a(n-3) + 4*a(n-4) - a(n-6) for n>12. Empirical g.f.: 2*x^2*(210 - 280*x - 606*x^2 + 785*x^3 + 376*x^4 - 525*x^5 - 39*x^6 + 180*x^7 + 36*x^8 - 6*x^9 - 3*x^10) / ((1 - x)^2*(1 - x - x^2)^2). - Colin Barker, Feb 18 2019 EXAMPLE Some solutions for n=4: ..0..1..1..0. .0..0..1..0. .0..0..1..1. .0..0..1..0. .0..1..1..0 ..0..0..1..1. .1..1..0..1. .1..0..0..1. .1..0..1..0. .0..0..1..0 ..1..0..0..1. .0..1..0..1. .1..1..0..0. .0..1..1..0. .1..0..1..0 ..1..1..0..1. .1..0..1..0. .0..1..1..0. .1..0..1..0. .1..1..1..0 ..0..1..1..0. .1..0..1..1. .1..0..1..1. .1..0..1..0. .1..0..1..1 ..0..1..0..1. .1..0..0..1. .1..0..0..1. .1..0..1..1. .1..0..0..1 CROSSREFS Row 6 of A281205. Sequence in context: A169825 A135196 A259025 * A235233 A251084 A250383 Adjacent sequences: A281207 A281208 A281209 * A281211 A281212 A281213 KEYWORD nonn AUTHOR R. H. Hardin, Jan 17 2017 STATUS approved

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Last modified January 27 13:15 EST 2023. Contains 359840 sequences. (Running on oeis4.)