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A253020 Number of (n+2) X (3+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
51, 83, 133, 120, 219, 350, 302, 531, 846, 754, 1323, 2100, 1888, 3287, 5198, 4734, 8185, 12894, 11890, 20411, 32028, 29912, 50981, 79678, 75374, 127541, 198526, 190242, 319593, 495428, 480944, 802149, 1238334, 1217806, 2016627, 3100254 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 5*a(n-3) - 6*a(n-6) - a(n-9) + a(n-12) for n>15.
Empirical g.f.: x*(51 + 83*x + 133*x^2 - 135*x^3 - 196*x^4 - 315*x^5 + 8*x^6 - 66*x^7 - 106*x^8 + 15*x^9 + 65*x^10 + 103*x^11 - x^12 - 6*x^13 - 9*x^14) / ((1 - 3*x^3 + x^6)*(1 - 2*x^3 - x^6)). - Colin Barker, Dec 08 2018
EXAMPLE
Some solutions for n=4:
..0..1..2..0..1....0..0..0..0..0....0..0..0..0..0....0..1..2..0..3
..1..0..2..1..0....1..2..0..1..2....1..2..0..1..2....2..2..2..2..2
..2..2..2..2..2....2..1..0..2..1....2..1..0..2..1....3..0..2..1..0
..0..1..2..0..3....0..0..0..0..0....0..0..0..0..0....0..3..2..0..1
..1..0..2..3..0....1..2..0..1..3....3..2..0..1..3....2..2..2..2..2
..2..2..2..2..2....2..3..0..2..1....2..1..0..2..1....3..0..2..3..0
CROSSREFS
Column 3 of A253025.
Sequence in context: A113285 A050698 A039474 * A351026 A020180 A049328
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 26 2014
STATUS
approved

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Last modified July 14 12:35 EDT 2024. Contains 374318 sequences. (Running on oeis4.)