cp's OEIS Frontend

A199907 Number of -6..6 arrays x(0..n-1) of n elements with zero sum, and adjacent elements not equal modulo three (with -1 modulo 3 = 2).

%I A199907 #7 Jun 02 2025 05:25:22
%S A199907 1,8,84,448,3196,29864,216530,1699268,14546928,116482068,950119628,
%T A199907 7969545520,65812921362,546169532636,4575686136942,38231452993064,
%U A199907 320077674218718,2689588505089064,22606933344228744,190257872374203952
%N A199907 Number of -6..6 arrays x(0..n-1) of n elements with zero sum, and adjacent elements not equal modulo three (with -1 modulo 3 = 2).
%C A199907 Column 6 of A199909
%H A199907 R. H. Hardin, <a href="/A199907/b199907.txt">Table of n, a(n) for n = 1..200</a>
%e A199907 Some solutions for n=6
%e A199907 .-6...-3...-2....0...-5....2....6...-4...-3....0....4....2...-3....2...-5....4
%e A199907 ..2...-1....2...-1....5....4...-2....4...-2....1...-4....1...-4...-5...-4...-4
%e A199907 ..1....6....0...-5....0...-1...-4...-6....5...-3....0...-3....4...-6....6....3
%e A199907 ..5....1....1....5...-5...-6...-2...-2....1...-2....2....5....0....1....4...-2
%e A199907 .-2...-1...-4...-3....5...-5....3....5...-1....6....1...-5...-2....5...-4....2
%e A199907 ..0...-2....3....4....0....6...-1....3....0...-2...-3....0....5....3....3...-3
%K A199907 nonn
%O A199907 1,2
%A A199907 _R. H. Hardin_ Nov 11 2011