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 A231317 Number of (n+1) X (1+1) 0..2 arrays with no element equal to a strict majority of its diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order. 2
 6, 24, 216, 1536, 11616, 86400, 645504, 4816896, 35956224, 268376064, 2003195904, 14952038400, 111603572736, 833020329984, 6217748545536, 46409906651136, 346408259813376, 2585626450329600, 19299378566529024, 144052522724622336 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 1 of A231324. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 6*a(n-1) + 12*a(n-2) - 8*a(n-3). Conjectures from Colin Barker, Mar 18 2018: (Start) G.f.: 6*x*(1 - 2*x) / ((1 + 2*x)*(1 - 8*x + 4*x^2)). a(n) = ((-2)^(1+n) + (4-2*sqrt(3))^n + (2*(2+sqrt(3)))^n) / 2. (End) EXAMPLE Some solutions for n=4: ..0..0....0..1....0..1....0..0....0..1....0..1....0..0....0..1....0..1....0..0 ..1..1....2..2....0..2....1..1....2..2....2..2....1..2....0..2....2..1....1..2 ..2..1....1..2....0..0....0..0....0..2....0..1....0..1....1..2....2..1....0..1 ..2..2....1..0....1..1....1..0....0..1....2..0....0..1....2..1....1..2....0..2 ..1..0....1..2....2..0....1..2....0..2....1..1....0..1....0..0....1..0....1..2 CROSSREFS Cf. A231324. Sequence in context: A320944 A277985 A091097 * A223105 A112675 A052583 Adjacent sequences:  A231314 A231315 A231316 * A231318 A231319 A231320 KEYWORD nonn AUTHOR R. H. Hardin, Nov 07 2013 STATUS approved

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Last modified June 18 18:06 EDT 2021. Contains 345120 sequences. (Running on oeis4.)