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A207302 Number of n X 5 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 1 0 vertically. 1

%I #10 Jun 21 2018 14:29:53

%S 13,169,665,1759,3773,7093,12169,19515,29709,43393,61273,84119,112765,

%T 148109,191113,242803,304269,376665,461209,559183,671933,800869,

%U 947465,1113259,1299853,1508913,1742169,2001415,2288509,2605373,2953993,3336419

%N Number of n X 5 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 1 0 vertically.

%C Column 5 of A207305.

%H R. H. Hardin, <a href="/A207302/b207302.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = (8/3)*n^4 + (49/3)*n^3 + (16/3)*n^2 - (43/3)*n + 3.

%F Conjectures from _Colin Barker_, Jun 21 2018: (Start)

%F G.f.: x*(13 + 104*x - 50*x^2 - 6*x^3 + 3*x^4) / (1 - x)^5.

%F a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.

%F (End)

%e Some solutions for n=4:

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

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

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

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

%Y Cf. A207305.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 16 2012

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Last modified September 10 06:17 EDT 2024. Contains 375773 sequences. (Running on oeis4.)