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A229006 Number of arrays of median of three adjacent elements of some length n+2 0..2 array, with no adjacent equal elements in the latter. 1

%I

%S 3,7,15,31,57,105,193,353,653,1209,2241,4161,7719,14325,26581,49311,

%T 91489,169729,314881,584177,1083761,2010609,3730105,6920121,12838307,

%U 23817773,44187025,81976335,152083481,282147169,523442893,971097649

%N Number of arrays of median of three adjacent elements of some length n+2 0..2 array, with no adjacent equal elements in the latter.

%H R. H. Hardin, <a href="/A229006/b229006.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) - a(n-3) + 2*a(n-5) - a(n-6) + 2*a(n-8) - a(n-9) + 2*a(n-11) - 2*a(n-12) + 2*a(n-13).

%F Empirical g.f.: x*(3 + x + x^2 + 4*x^3 + 2*x^4 + 3*x^6 + x^7 - x^8 + 2*x^9 - 2*x^11 + 2*x^12) / (1 - 2*x + x^3 - 2*x^5 + x^6 - 2*x^8 + x^9 - 2*x^11 + 2*x^12 - 2*x^13). - _Colin Barker_, Sep 13 2018

%e Some solutions for n=4:

%e ..0....1....1....0....0....1....1....2....1....2....0....1....1....2....1....1

%e ..2....1....2....1....1....0....1....0....1....1....2....1....2....1....1....0

%e ..1....0....0....1....0....1....1....1....2....1....1....1....0....2....1....1

%e ..1....1....2....1....1....0....2....0....0....0....2....1....1....1....0....1

%Y Column 2 of A229012.

%K nonn

%O 1,1

%A _R. H. Hardin_, Sep 10 2013

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Last modified September 19 09:00 EDT 2020. Contains 337178 sequences. (Running on oeis4.)