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A262268 Number of (n+2) X (2+2) 0..1 arrays with each row and column divisible by 5, read as a binary number with top and left being the most significant bits. 1

%I #7 Dec 31 2018 05:46:00

%S 4,16,49,169,676,2704,10609,42025,168100,672400,2686321,10738729,

%T 42954916,171819664,687226225,2748800041,10995200164,43980800656,

%U 175922363761,703687777321,2814751109284,11259004437136,45036004326769

%N Number of (n+2) X (2+2) 0..1 arrays with each row and column divisible by 5, read as a binary number with top and left being the most significant bits.

%H R. H. Hardin, <a href="/A262268/b262268.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 6*a(n-1) - 12*a(n-2) + 24*a(n-3) - 31*a(n-4) - 6*a(n-5) + 12*a(n-6) - 24*a(n-7) + 32*a(n-8).

%F Empirical g.f.: x*(4 - 8*x + x^2 - 29*x^3 - 10*x^4 + 20*x^5 + 8*x^6 + 32*x^7) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 - 4*x)*(1 + x^2)*(1 + 4*x^2)). - _Colin Barker_, Dec 31 2018

%e Some solutions for n=4:

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

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

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

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

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

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

%Y Column 2 of A262274.

%K nonn

%O 1,1

%A _R. H. Hardin_, Sep 17 2015

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Last modified August 12 19:26 EDT 2024. Contains 375113 sequences. (Running on oeis4.)