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 A252956 Number of (n+2) X (3+2) 0..4 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
 223, 155, 259, 443, 871, 1681, 2999, 6103, 11983, 21749, 44515, 88087, 161123, 330817, 656011, 1210571, 2483599, 4939057, 9174815, 18819943, 37462903, 70101461, 143554507, 286165735, 538738571, 1101824353, 2197577587, 4162662491 (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) = 4*a(n-1) - 2*a(n-2) - 3*a(n-3) - 13*a(n-4) + 8*a(n-5) + 70*a(n-6) - 105*a(n-7) + 42*a(n-8) for n>10. Empirical g.f.: x*(223 - 737*x + 85*x^2 + 386*x^3 + 2981*x^4 + 91*x^5 - 14137*x^6 + 16334*x^7 - 4830*x^8 - 420*x^9) / ((1 - x)^2*(1 - 2*x)*(1 - 3*x^2)*(1 - 7*x^3)). - Colin Barker, Dec 07 2018 EXAMPLE Some solutions for n=2: ..0..1..1..2..2....0..1..1..2..2....0..1..1..0..1....0..1..1..2..2 ..3..0..0..1..1....3..0..0..4..4....0..2..0..0..2....3..0..0..1..1 ..2..4..4..0..4....2..3..3..1..1....0..0..2..0..0....2..3..3..0..0 ..1..3..3..4..3....4..2..2..0..0....0..1..1..0..1....1..4..4..3..3 CROSSREFS Column 3 of A252961. Sequence in context: A268017 A267978 A234623 * A163653 A178551 A105982 Adjacent sequences:  A252953 A252954 A252955 * A252957 A252958 A252959 KEYWORD nonn AUTHOR R. H. Hardin, Dec 25 2014 STATUS approved

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Last modified December 5 18:32 EST 2021. Contains 349557 sequences. (Running on oeis4.)