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Number of n X n arrays of squares of integers with every (n-1)X(n-1) subblock summing to 4
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%I #8 Dec 18 2015 18:17:19

%S 9,767,19252,182643,1036981,4279949,14199872,40175697,100665373,

%T 229182711,482835464,954070027,1786340817,3194495053,5490736316,

%U 9117102929,14685469857,23026155487,35246287308,52799153171,77565837469

%N Number of n X n arrays of squares of integers with every (n-1)X(n-1) subblock summing to 4

%H R. H. Hardin, <a href="/A159356/b159356.txt">Table of n, a(n) for n=3..34</a>

%F Empirical (for n>=3): a(n) = 1/288*(519*n^8 - 6716*n^7 + 34142*n^6 - 78248*n^5 + 32735*n^4 + 236596*n^3 - 555412*n^2 + 518112*n - 185184). - _Vaclav Kotesovec_, Nov 30 2012

%F Empirical G.f.: -x^2 + x^2*(-1 - 722*x^2 - 12589*x^3 - 36357*x^4 - 22846*x^5 - 692*x^6 + 535*x^7 + 12*x^8)/(-1+x)^9. - _Vaclav Kotesovec_, Nov 30 2012

%K nonn

%O 3,1

%A _R. H. Hardin_ Apr 11 2009