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Number of nXnXn triangular 0..3 arrays with some element plus some adjacent element totalling 3+1 exactly once.
0

%I #3 Mar 18 2016 08:00:49

%S 0,21,1137,132474,34889103,22383193638,35714928884139,

%T 144182981347081503,1486449414781831854123,39397028534591054436055983,

%U 2696910972157269626108160017520,478461426234650496975341723139740316

%N Number of nXnXn triangular 0..3 arrays with some element plus some adjacent element totalling 3+1 exactly once.

%C Column 3 of A270509.

%e Some solutions for n=4

%e .....3........1........0........0........0........2........0........0

%e ....0.3......2.0......1.1......2.1......1.1......0.2......0.0......0.0

%e ...0.2.1....0.1.0....2.0.2....0.1.0....0.1.2....1.0.1....3.3.3....3.2.1

%e ..1.1.1.1..2.0.3.2..0.3.3.1..3.1.0.2..0.0.3.3..0.0.0.2..3.2.2.0..3.0.0.3

%Y Cf. A270509.

%K nonn

%O 1,2

%A _R. H. Hardin_, Mar 18 2016