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 A210136 Number of (n+1) X 2 0..3 arrays containing all values 0..3 with every 2 X 2 subblock having one, two or four distinct values, and new values 0..3 introduced in row major order. 1
 1, 10, 105, 1018, 9157, 77934, 638065, 5084818, 39762621, 306822358, 2345284009, 17806600698, 134548145461, 1013159874046, 7610346917985, 57063648570850, 427326717363757, 3197140079770278, 23904313586774425, 178642318573382986 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Column 1 of A210143. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 18*a(n-1) - 111*a(n-2) + 266*a(n-3) - 180*a(n-4) - 24*a(n-5) + 32*a(n-6). Empirical g.f.: x*(1 - 8*x + 36*x^2 - 28*x^3 + 8*x^4) / ((1 - x)*(1 - 4*x)*(1 - 5*x - 2*x^2)*(1 - 8*x + 4*x^2)). - Colin Barker, Jul 14 2018 EXAMPLE Some solutions for n=4:   0 0   0 0   0 0   0 1   0 0   0 1   0 0   0 0   0 1   0 0   1 0   0 1   1 0   0 0   0 0   0 0   0 0   0 0   1 0   0 0   0 0   2 3   0 1   1 1   0 0   1 0   0 0   0 1   2 3   1 1   2 2   0 1   0 1   0 1   0 1   1 0   1 0   2 3   3 2   0 1   2 3   3 2   2 3   2 3   2 3   2 3   2 3   2 3   0 1   2 3 CROSSREFS Cf. A210143. Sequence in context: A117832 A268763 A300850 * A068093 A260214 A077369 Adjacent sequences:  A210133 A210134 A210135 * A210137 A210138 A210139 KEYWORD nonn AUTHOR R. H. Hardin, Mar 17 2012 STATUS approved

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Last modified December 8 03:17 EST 2021. Contains 349590 sequences. (Running on oeis4.)