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 A278623 #6 Apr 14 2023 15:37:10 %S A278623 51,1952,49503,1069536,21121532,387542112,6594175430,103536313036, %T A278623 1496475492375,19928249063688,245280439959902,2802425055340520, %U A278623 29863427285241827,298206737876251916,2802780797553511873 %N A278623 Number of n X 4 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly one mistake. %C A278623 Column 4 of A278627. %H A278623 R. H. Hardin, <a href="/A278623/b278623.txt">Table of n, a(n) for n = 1..210</a> %H A278623 R. H. Hardin, <a href="/A278623/a278623.txt">Empirical polynomial of degree 125</a> %F A278623 Empirical polynomial of degree 125 (see link above). %e A278623 Some solutions for n=3 %e A278623 ..0..2..2..0. .1..1..0..0. .1..1..1..0. .0..0..1..0. .1..1..1..0 %e A278623 ..2..0..0..2. .1..1..1..2. .2..1..0..2. .1..1..0..1. .2..0..0..1 %e A278623 ..2..2..0..0. .1..1..2..2. .0..1..0..0. .2..1..1..2. .1..0..0..2 %Y A278623 Cf. A278627. %K A278623 nonn %O A278623 1,1 %A A278623 _R. H. Hardin_, Nov 24 2016