%I #13 Aug 06 2023 21:55:02
%S 0,5,64,629,5632,48485,410944,3470549,29389312,250334405
%N Number of collinear point 4-tuples in a 5 X 5 X 5 X... n-dimensional cubic grid
%F Conjecture: a(n) = 9^n/2+3*7^n/2-2*5^n. a(n)= +21*a(n-1) -143*a(n-2) +315*a(n-3). G.f.: x*(-5+41*x)/((9*x-1)*(7*x-1)*(5*x-1)). [_R. J. Mathar_, May 24 2010]
%K nonn
%O 0,2
%A _R. H. Hardin_, suggested by R. J. Mathar in the Sequence Fans Mailing List, May 24 2010
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