cp's OEIS Frontend

A229693 Number of defective 3-colorings of an n X 7 0..2 array connected horizontally and antidiagonally with exactly two mistakes, and colors introduced in row-major 0..2 order.

%I A229693 #8 Apr 28 2021 01:22:24
%S A229693 120,20691,1400413,75035643,3583403667,159377253183,6749642728251,
%T A229693 275739382892979,10957241965280031,425954258229381831,
%U A229693 16265054107660003947,611918047133484899067,22734198484723715670855
%N A229693 Number of defective 3-colorings of an n X 7 0..2 array connected horizontally and antidiagonally with exactly two mistakes, and colors introduced in row-major 0..2 order.
%C A229693 Column 7 of A229694.
%H A229693 R. H. Hardin, <a href="/A229693/b229693.txt">Table of n, a(n) for n = 1..210</a>
%F A229693 Empirical: a(n) = 126*a(n-1) - 6345*a(n-2) + 165456*a(n-3) - 2474469*a(n-4) + 22918302*a(n-5) - 138045627*a(n-6) + 554666940*a(n-7) - 1494608922*a(n-8) + 2659094568*a(n-9) - 2986698420*a(n-10) + 1913187600*a(n-11) - 531441000*a(n-12) for n > 14.
%e A229693 Some solutions for n=3:
%e A229693   0 0 1 2 1 2 1      0 0 1 0 1 2 1      0 0 1 0 1 2 0
%e A229693   1 0 1 2 1 2 2      1 2 1 0 1 0 2      1 0 2 0 2 1 2
%e A229693   1 2 1 2 1 0 2      1 2 0 2 1 0 2      2 1 2 1 0 1 0
%K A229693 nonn
%O A229693 1,1
%A A229693 _R. H. Hardin_, Sep 27 2013