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A252718 Number of (n+2) X (7+2) 0..3 arrays with every consecutive three elements in every row and diagonal having exactly two distinct values, and in every column and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order. 1
237, 107, 114, 153, 211, 270, 373, 522, 672, 938, 1322, 1704, 2388, 3379, 4354, 6113, 8673, 11166, 15693, 22312, 28696, 40358, 57486, 73856, 103928, 148285, 190314, 267933, 382891, 490926, 691453, 989592, 1267608, 1786118, 2559836, 3276048 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 6*a(n-3) - 11*a(n-6) + 5*a(n-9) + 2*a(n-12) - a(n-15) for n>17.
Empirical g.f.: x*(237 + 107*x + 114*x^2 - 1269*x^3 - 431*x^4 - 414*x^5 + 2062*x^6 + 433*x^7 + 306*x^8 - 802*x^9 - 24*x^10 + 72*x^11 - 376*x^12 - 80*x^13 - 56*x^14 + 169*x^15 + 16*x^16) / ((1 - x)*(1 + x + x^2)*(1 - 3*x^3 + x^6)*(1 - 2*x^3 - x^6)). - Colin Barker, Dec 05 2018
EXAMPLE
Some solutions for n=4:
..0..0..1..0..0..2..0..0..2....0..1..0..0..1..0..0..1..0
..2..0..0..1..0..0..2..0..0....1..1..2..1..1..3..1..1..3
..3..0..3..3..0..3..3..0..3....3..1..1..2..1..1..3..1..1
..0..0..2..0..0..1..0..0..2....0..1..0..0..1..0..0..1..0
..1..0..0..2..0..0..1..0..0....1..1..3..1..1..2..1..1..3
..3..0..3..3..0..3..3..0..3....2..1..1..3..1..1..2..1..1
CROSSREFS
Column 7 of A252719.
Sequence in context: A233200 A233221 A265372 * A036270 A217030 A048454
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 20 2014
STATUS
approved

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Last modified March 29 05:28 EDT 2024. Contains 371264 sequences. (Running on oeis4.)