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A228479 Number of n X 5 binary arrays with top left value 1 and no two ones adjacent horizontally, vertically or antidiagonally. 1

%I #11 Sep 11 2018 09:05:57

%S 5,19,127,728,4354,25699,152373,902042,5342712,31639786,187379548,

%T 1109702480,6571916787,38920392611,230495519461,1365047364511,

%U 8084124028133,47876038862427,283532896714060,1679146925634733

%N Number of n X 5 binary arrays with top left value 1 and no two ones adjacent horizontally, vertically or antidiagonally.

%C Same recurrences as A228285 except in addition this smaller one for this column.

%H R. H. Hardin, <a href="/A228479/b228479.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) + 15*a(n-2) + 16*a(n-3) - 11*a(n-4) - 20*a(n-5) + 19*a(n-6) - 8*a(n-7) + a(n-9).

%F Empirical g.f.: x*(5 + 4*x - 5*x^2 - 18*x^3 + 16*x^4 - 6*x^5 + x^7) / (1 - 3*x - 15*x^2 - 16*x^3 + 11*x^4 + 20*x^5 - 19*x^6 + 8*x^7 - x^9). - _Colin Barker_, Sep 11 2018

%e Some solutions for n=4:

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

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

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

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

%Y Column 5 of A228482.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 22 2013

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Last modified April 16 16:49 EDT 2024. Contains 371749 sequences. (Running on oeis4.)