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A252530 Number of (n+2) X (6+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 2 3 6 or 7. 1

%I #8 Dec 04 2018 11:04:10

%S 932,1000,1760,2440,7184,13184,18656,54464,101888,145792,423680,

%T 800768,1152512,3341312,6348800,9164800,26537984,50561024,73097216,

%U 211533824,403570688,583892992,1689190400,3224895488,4667604992,13501202432

%N Number of (n+2) X (6+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 2 3 6 or 7.

%H R. H. Hardin, <a href="/A252530/b252530.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 12*a(n-3) - 32*a(n-6) for n>8.

%F Empirical g.f.: 4*x*(233 + 250*x + 440*x^2 - 2186*x^3 - 1204*x^4 - 1984*x^5 + 4800*x^6 + 64*x^7) / ((1 - 2*x)*(1 + 2*x + 4*x^2)*(1 - 4*x^3)). - _Colin Barker_, Dec 04 2018

%e Some solutions for n=4:

%e ..0..1..1..0..1..1..0..1....2..2..3..2..2..3..2..2....2..0..0..3..0..0..3..3

%e ..1..0..1..1..0..1..1..0....3..2..2..3..2..2..3..2....1..0..1..1..0..1..1..0

%e ..0..0..2..0..0..3..0..0....3..0..3..3..1..3..3..0....1..1..0..1..1..0..1..1

%e ..0..1..1..0..1..1..0..1....2..2..3..2..2..3..2..2....3..0..0..3..0..0..3..0

%e ..1..0..1..1..0..1..1..0....3..2..2..3..2..2..3..2....1..0..1..1..0..1..1..0

%e ..0..0..3..0..0..2..0..0....3..0..3..3..0..3..3..0....1..1..0..1..1..0..1..1

%Y Column 6 of A252532.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 18 2014

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Last modified August 13 07:44 EDT 2024. Contains 375113 sequences. (Running on oeis4.)