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A207304 Number of n X 7 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 1 0 vertically. 1

%I #9 Jun 22 2018 07:08:36

%S 28,784,4344,14446,36868,79802,154228,274288,457660,725932,1104976,

%T 1625322,2322532,3237574,4417196,5914300,7788316,10105576,12939688,

%U 16371910,20491524,25396210,31192420,37995752,45931324,55134148,65749504

%N Number of n X 7 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 1 0 vertically.

%C Column 7 of A207305.

%H R. H. Hardin, <a href="/A207304/b207304.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = (187/60)*n^5 + (153/4)*n^4 + (455/12)*n^3 - (249/4)*n^2 + (209/30)*n + 4.

%F Conjectures from _Colin Barker_, Jun 22 2018: (Start)

%F G.f.: 2*x*(14 + 308*x + 30*x^2 - 209*x^3 + 46*x^4 - 2*x^5) / (1 - x)^6.

%F a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.

%F (End)

%e Some solutions for n=4:

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

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

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

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

%Y Cf. A207305.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 16 2012

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Last modified April 24 13:00 EDT 2024. Contains 371945 sequences. (Running on oeis4.)