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 A229698 #8 Apr 28 2021 01:22:20 %S A229698 0,2304,62856,1125333,17724789,258006388,3583403667,48115029568, %T A229698 629879095575,8082470014816,102040738816275,1270988929203520, %U A229698 15651508367076687,190863964416217648,2307849686574725259 %N A229698 Number of defective 3-colorings of a 5 X n 0..2 array connected horizontally and antidiagonally with exactly two mistakes, and colors introduced in row-major 0..2 order. %C A229698 Row 5 of A229694. %H A229698 R. H. Hardin, <a href="/A229698/b229698.txt">Table of n, a(n) for n = 1..210</a> %F A229698 Empirical: a(n) = 48*a(n-1) - 960*a(n-2) + 10468*a(n-3) - 68685*a(n-4) + 282276*a(n-5) - 718624*a(n-6) + 997536*a(n-7) - 166467*a(n-8) - 2005784*a(n-9) + 3520224*a(n-10) - 1956780*a(n-11) - 1660207*a(n-12) + 3547332*a(n-13) - 2236608*a(n-14) - 28632*a(n-15) + 1014720*a(n-16) - 774528*a(n-17) + 307392*a(n-18) - 71424*a(n-19) + 9216*a(n-20) - 512*a(n-21) for n > 27. %e A229698 Some solutions for n=3: %e A229698 0 1 0 0 1 0 0 1 0 0 0 1 0 0 1 0 1 0 0 1 0 %e A229698 2 1 2 2 1 0 2 0 1 1 0 2 1 0 2 2 2 1 2 1 0 %e A229698 0 1 0 2 1 2 2 0 1 2 0 1 1 0 2 0 2 1 2 2 1 %e A229698 2 0 1 1 2 0 2 1 2 1 0 2 1 0 1 1 0 2 1 0 1 %e A229698 0 2 0 0 2 0 2 0 2 1 2 1 2 0 0 1 0 0 0 2 1 %K A229698 nonn %O A229698 1,2 %A A229698 _R. H. Hardin_, Sep 27 2013