|
%I #9 Dec 18 2015 18:17:19
%S 42,158,426,1202,2970,8234,20538,58202,148602,430778,1120506,3298682,
%T 8679930,25783034,68281338,203806202,541575162,1620552698
%N Number of n X n arrays of squares of integers with every 2X2 subblock summing to 26
%F Empirical (for n>=2): a(n) = 7*2^(n/2-1)*((3*sqrt(2)-4)*(-1)^n-3*sqrt(2)-4) + (-2)^(n-1) + 37*2^(n-1) + 2^(3*n/2-1)*((4-3*sqrt(2))*(-1)^n+3*sqrt(2)+4)-6. - _Vaclav Kotesovec_, Nov 30 2012
%F Empirical G.f.: 12-2*x + 2*(-6 + 7*x + 104*x^2 - 40*x^3 - 482*x^4 - 32*x^5 + 512*x^6)/((-1+x)*(-1+2*x)*(1+2*x)*(-1+2*x^2)*(-1+8*x^2)). - _Vaclav Kotesovec_, Nov 30 2012
%K nonn
%O 2,1
%A _R. H. Hardin_ Apr 06 2009
|
