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%I #9 May 27 2016 03:13:23
%S 0,252,2624,14259,55748,177136,486512,1197675,2705424,5699396,
%T 11330072,21443587
%N Number of nX3 1..4 arrays containing at least one of each value, all equal values connected, and rows considered as a single number in nondecreasing order.
%F From _G. C. Greubel_, May 26 2016: (Start)
%F Empirical a(n) = (1/45360)*(n-1)*(226800 - 555696*n + 563760*n^2 + 340780*n^3 + 306823*n^4 + 52219*n^5 + 10513*n^6 + 553*n^7 + 40*n^8).
%F Empirical G.f.: x^2*(5*x^8 + 6*x^7 - 23*x^6 + 268*x^5 - 649*x^4 + 998*x^3 - 641*x^2 + 104*x + 252)/(1-x)^10. (End)
%e Some solutions for n=3
%e ...3.1.3...3.1.2...2.2.1...1.1.4...1.2.2...1.1.2...3.3.3...1.1.4...1.4.3
%e ...3.3.3...4.4.4...2.3.1...1.2.2...2.2.4...4.3.2...3.3.3...1.2.4...1.4.3
%e ...4.3.2...4.4.4...4.3.3...3.3.3...2.3.4...4.3.2...4.2.1...1.3.4...2.2.2
%e ------
%e ...3.2.1...2.3.1...2.2.2...1.1.1...2.3.1...1.2.2...1.1.1...1.1.1...1.1.1
%e ...3.2.1...4.4.1...2.3.3...1.3.2...3.3.1...4.4.2...2.3.3...2.2.2...4.3.3
%e ...4.1.1...4.4.1...4.1.1...4.4.4...3.4.1...4.4.3...3.3.4...4.2.3...4.4.2
%K nonn
%O 1,2
%A _R. H. Hardin_, Oct 21 2009
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