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%I #5 Apr 04 2016 13:40:13
%S 0,1,15,207,3283,64650,1640007,54704700,2429994600,144950275305,
%T 11678538065077,1276251983814717,189767651505152535,
%U 38484504169958401936,10664509514660169498882,4044220867954839169651680
%N Number of nXnXn triangular 0..1 arrays with new values introduced in sequential zero-upwards order and exactly one upright 2x2x2 triangle having values all equal.
%C Column 1 of A271339.
%H R. H. Hardin, <a href="/A271333/b271333.txt">Table of n, a(n) for n = 1..20</a>
%e Some solutions for n=4
%e .....0........0........0........0........0........0........0........0
%e ....1.1......0.1......0.1......1.0......0.1......1.1......1.0......0.1
%e ...0.1.0....1.1.1....1.0.0....1.1.0....1.1.0....1.0.1....1.0.0....0.0.0
%e ..0.0.0.1..0.1.0.1..1.1.1.1..0.0.1.0..1.0.0.0..0.0.0.0..0.0.1.1..0.1.1.1
%Y Cf. A271339.
%K nonn
%O 1,3
%A _R. H. Hardin_, Apr 04 2016