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 A253018 Number of (n+2) X (1+2) 0..3 arrays with every consecutive three elements in every row and column not having exactly two distinct values, and in every diagonal and antidiagonal having exactly two distinct values, and new values 0 upwards introduced in row major order. 1
 25, 37, 51, 63, 105, 153, 189, 315, 459, 567, 945, 1377, 1701, 2835, 4131, 5103, 8505, 12393, 15309, 25515, 37179, 45927, 76545, 111537, 137781, 229635, 334611, 413343, 688905, 1003833, 1240029, 2066715, 3011499, 3720087, 6200145, 9034497, 11160261 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 3*a(n-3) for n>5. Empirical g.f.: x*(25 + 37*x + 51*x^2 - 12*x^3 - 6*x^4) / (1 - 3*x^3). - Colin Barker, Dec 08 2018 EXAMPLE Some solutions for n=4: ..0..1..2....0..0..0....0..1..2....0..1..2....0..0..0....0..1..2....0..1..2 ..2..1..0....1..0..2....0..0..0....3..1..0....1..2..0....2..2..2....3..0..2 ..1..1..1....2..0..3....0..2..1....1..1..1....2..1..0....1..3..2....2..2..2 ..0..1..2....0..0..0....0..1..2....0..1..3....0..0..0....3..1..2....1..3..2 ..2..1..0....3..0..2....0..0..0....2..1..0....1..2..0....2..2..2....3..1..2 ..1..1..1....2..0..3....0..2..1....1..1..1....2..3..0....1..0..2....2..2..2 CROSSREFS Column 1 of A253025. Sequence in context: A079270 A253025 A127022 * A120148 A038516 A080386 Adjacent sequences: A253015 A253016 A253017 * A253019 A253020 A253021 KEYWORD nonn AUTHOR R. H. Hardin, Dec 26 2014 STATUS approved

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Last modified June 22 15:57 EDT 2024. Contains 373590 sequences. (Running on oeis4.)