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A207935 Number of n X 5 0..1 arrays avoiding 0 0 1 and 1 0 0 horizontally and 0 0 1 and 1 1 0 vertically. 1

%I #8 Jun 26 2018 06:25:12

%S 14,196,844,2422,5594,11256,20568,34986,56294,86636,128548,184990,

%T 259378,355616,478128,631890,822462,1056020,1339388,1680070,2086282,

%U 2566984,3131912,3791610,4557462,5441724,6457556,7619054,8941282,10440304

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

%C Column 5 of A207938.

%H R. H. Hardin, <a href="/A207935/b207935.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: 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).

%F Conjectures from _Colin Barker_, Jun 26 2018: (Start)

%F G.f.: 2*x*(7 + 56*x - 61*x^2 + 9*x^3 + 6*x^4 - x^5) / (1 - x)^6.

%F a(n) = (30 - 149*n + 10*n^2 + 250*n^3 + 65*n^4 + 4*n^5) / 15.

%F (End)

%e Some solutions for n=4:

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

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

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

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

%Y Cf. A207938.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 21 2012

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Last modified March 28 11:59 EDT 2024. Contains 371254 sequences. (Running on oeis4.)