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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 R. H. Hardin, Table of n, a(n) for n = 1..210 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 Adjacent sequences: A252715 A252716 A252717 * A252719 A252720 A252721 KEYWORD nonn AUTHOR R. H. Hardin, Dec 20 2014 STATUS approved

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Last modified March 27 02:29 EDT 2023. Contains 361553 sequences. (Running on oeis4.)