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 A228504 Number of n X 6 binary arrays with top left value 1 and no two ones adjacent horizontally, vertically, diagonally or antidiagonally. 1

%I #10 Sep 12 2018 06:13:36

%S 8,21,239,1252,9528,59839,413786,2724191,18387032,122539084,821945828,

%T 5495164996,36800032261,246231184011,1648269251345,11031030456148,

%U 73833534042745,494158034052549,3307432804186754,22136531409536410

%N Number of n X 6 binary arrays with top left value 1 and no two ones adjacent horizontally, vertically, diagonally or antidiagonally.

%H R. H. Hardin, <a href="/A228504/b228504.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) + 30*a(n-2) - 17*a(n-3) - 138*a(n-4) + 85*a(n-5) + 116*a(n-6) - 42*a(n-7) - 32*a(n-8).

%F Empirical g.f.: x*(8 - 3*x - 64*x^2 + 41*x^3 + 63*x^4 - 24*x^5 - 18*x^6) / (1 - 3*x - 30*x^2 + 17*x^3 + 138*x^4 - 85*x^5 - 116*x^6 + 42*x^7 + 32*x^8). - _Colin Barker_, Sep 12 2018

%e Some solutions for n=4:

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

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

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

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

%Y Column 6 of A228506.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 23 2013

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Last modified June 23 00:47 EDT 2024. Contains 373629 sequences. (Running on oeis4.)