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 A159229 1/16 the number of n X n arrays of squares of integers with every 2X2 subblock summing to 30 0

%I

%S 3,11,29,77,189,509,1277,3581,9213,26621,69629,204797,540669,1605629,

%T 4259837,12713981,33816573,101187581

%N 1/16 the number of n X n arrays of squares of integers with every 2X2 subblock summing to 30

%F Empirical (for n>=2): a(n) = 2^(3*(n-3)/2) * ((2*sqrt(2)-3)*(-1)^n + 2*sqrt(2) + 3) + 2^n-3. - _Vaclav Kotesovec_, Nov 30 2012

%F Empirical G.f.: 7/4+x/4 + (7 - 20*x - 57*x^2 + 154*x^3)/(4*(-1+x)*(-1+2*x)*(-1+8*x^2)). - _Vaclav Kotesovec_, Nov 30 2012

%K nonn

%O 2,1

%A _R. H. Hardin_ Apr 06 2009

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Last modified December 5 20:39 EST 2021. Contains 349558 sequences. (Running on oeis4.)