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 A222776 Number of n X 1 0..6 arrays with no element equal to another at a city block distance of exactly two, and new values 0..6 introduced in row major order. 1
 1, 2, 3, 7, 20, 67, 255, 1079, 4987, 24759, 129947, 710791, 4004619, 23031191, 134328379, 790907943, 4686298091, 27884452663, 166383085851, 994632987335, 5953222496203, 35661292725975, 213736364551163, 1281494949329767 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Column 1 of A222779. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 16*a(n-1) - 95*a(n-2) + 260*a(n-3) - 324*a(n-4) + 144*a(n-5) for n>7. Empirical g.f.: x*(1 + x)*(1 - 15*x + 81*x^2 - 192*x^3 + 189*x^4 - 53*x^5) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)*(1 - 6*x)). - Colin Barker, Aug 16 2018 EXAMPLE All solutions for n=3: ..0....0....0 ..1....1....0 ..2....1....1 CROSSREFS Cf. A222779. Sequence in context: A300041 A222939 A222867 * A222890 A011968 A080021 Adjacent sequences: A222773 A222774 A222775 * A222777 A222778 A222779 KEYWORD nonn AUTHOR R. H. Hardin, Mar 05 2013 STATUS approved

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Last modified December 5 03:48 EST 2023. Contains 367567 sequences. (Running on oeis4.)