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Number of n X n X n triangular 0..6 arrays with no element equal to the difference mod 7 of any two of its neighbors.
0

%I #6 Mar 15 2023 14:12:08

%S 7,216,3636,152574,21331380,7767784824,7384820647122,18209251766239734

%N Number of n X n X n triangular 0..6 arrays with no element equal to the difference mod 7 of any two of its neighbors.

%e Some solutions for 4 X 4 X 4

%e .....1........4........2........3........2........1........2........4

%e ....4.4......1.1......2.2......3.3......2.2......1.4......3.2......3.3

%e ...1.4.4....1.1.4....3.3.2....2.2.3....2.2.2....1.1.4....3.2.2....3.3.3

%e ..4.4.1.1..1.1.4.4..3.2.2.2..2.2.3.3..2.2.2.2..4.1.1.4..3.3.2.3..3.2.2.2

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 07 2011