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 A229592 #9 Apr 27 2021 21:29:51 %S A229592 0,26624,839808,25745364,752194836,21639043284,613195191972, %T A229592 17182547751528,476829713920572,13124502841956912,358700511256861500, %U A229592 9743787862523085312,263278493550185520600,7080841230759146337948 %N A229592 Number of defective 3-colorings of a 7 X n 0..2 array connected horizontally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order. %C A229592 Row 7 of A229586. %H A229592 R. H. Hardin, <a href="/A229592/b229592.txt">Table of n, a(n) for n = 1..210</a> %H A229592 R. H. Hardin, <a href="/A229592/a229592.txt">Empirical recurrence of order 54</a> %F A229592 Empirical recurrence of order 54 (see link above). %e A229592 Some solutions for n=3: %e A229592 0 1 0 0 1 0 0 1 0 0 0 1 0 0 1 0 1 0 0 1 0 %e A229592 0 1 0 0 1 0 0 1 0 1 2 1 2 0 1 0 1 0 0 1 0 %e A229592 0 2 1 0 2 0 0 1 2 1 0 2 2 0 1 0 1 2 2 2 0 %e A229592 1 2 0 1 2 0 0 1 0 1 0 2 2 0 2 1 0 2 0 2 1 %e A229592 1 2 0 1 0 2 2 1 0 2 1 2 2 1 2 1 0 2 1 2 0 %e A229592 0 1 2 2 0 1 0 1 2 0 1 2 0 1 0 1 0 2 0 1 2 %e A229592 0 1 1 2 0 2 1 0 2 2 1 2 0 2 1 1 0 2 2 0 1 %Y A229592 Cf. A229586. %K A229592 nonn %O A229592 1,2 %A A229592 _R. H. Hardin_, Sep 26 2013