This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A229700 #9 Apr 28 2021 01:23:37 %S A229700 0,79872,4377888,175867605,6279934941,210095323918,6749642728251, %T A229700 210585483358218,6425394969210939,192588353994919005, %U A229700 5688456451099770177,165962586614349710061,4791398443494607293804,137079252918696683881476 %N A229700 Number of defective 3-colorings of a 7 X n 0..2 array connected horizontally and antidiagonally with exactly two mistakes, and colors introduced in row-major 0..2 order. %C A229700 Row 7 of A229694. %H A229700 R. H. Hardin, <a href="/A229700/b229700.txt">Table of n, a(n) for n = 1..210</a> %H A229700 R. H. Hardin, <a href="/A229700/a229700.txt">Empirical recurrence of order 86</a> %F A229700 Empirical recurrence of order 86 (see link above). %e A229700 Some solutions for n=3: %e A229700 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 %e A229700 0 1 0 0 1 0 0 1 0 0 1 0 0 0 1 0 0 1 0 1 0 %e A229700 0 2 0 0 1 0 0 1 0 0 2 0 1 0 2 2 0 2 0 1 0 %e A229700 0 1 1 0 1 0 0 1 0 0 2 1 2 0 1 1 0 2 0 1 1 %e A229700 2 0 2 1 2 1 2 2 0 0 2 0 1 2 0 1 0 2 2 1 2 %e A229700 1 2 1 0 1 0 1 1 2 0 2 2 0 2 1 1 0 1 0 1 2 %e A229700 1 0 2 0 1 2 2 0 2 0 2 0 1 0 1 1 0 1 2 0 2 %K A229700 nonn %O A229700 1,2 %A A229700 _R. H. Hardin_, Sep 27 2013