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A220600 Number of ways to reciprocally link elements of an nX6 array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without 3-loops.

%I A220600 #6 Jul 23 2025 01:17:11
%S A220600 1,117,25747,3174778,352586943,41011388731,4807269151250,
%T A220600 561355035745825,65523075831128720,7650441027984730028,
%U A220600 893266330737712903338,104295209452828358545715,12177239947634323813819907
%N A220600 Number of ways to reciprocally link elements of an nX6 array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without 3-loops.
%C A220600 Column 6 of A220602
%H A220600 R. H. Hardin, <a href="/A220600/b220600.txt">Table of n, a(n) for n = 1..210</a>
%e A220600 Some solutions for n=3 0=self 2=n 3=ne 4=w 6=e 7=sw 8=s (reciprocal directions total 10)
%e A220600 .00.78.00.67.46.47...00.78.78.78.78.00...00.78.78.00.78.78...00.00.68.48.00.00
%e A220600 .38.26.34.78.38.00...38.23.23.23.26.47...38.23.27.37.23.28...68.48.26.24.67.47
%e A220600 .26.46.34.26.24.00...26.46.46.46.34.00...26.34.36.46.46.24...26.24.00.36.34.00
%K A220600 nonn
%O A220600 1,2
%A A220600 _R. H. Hardin_ Dec 16 2012