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 A278729 #4 Nov 27 2016 07:13:40 %S A278729 40,1947,58904,1410818,28637916,506031118,7907770636,110655824716, %T A278729 1401584381570,16222274394016,173007912264684,1712497545142699, %U A278729 15831976807688826,137451501603516285,1125976516897709842 %N A278729 Number of nX3 0..3 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly one mistake. %C A278729 Column 3 of A278734. %H A278729 R. H. Hardin, <a href="/A278729/b278729.txt">Table of n, a(n) for n = 1..210</a> %H A278729 R. H. Hardin, <a href="/A278729/a278729_1.txt">Empirical polynomial of degree 109</a> %F A278729 Empirical polynomial of degree 109 (see link above) %e A278729 Some solutions for n=3 %e A278729 ..2..2..1. .0..0..0. .1..0..0. .0..3..1. .3..1..1. .3..1..0. .2..0..0 %e A278729 ..1..1..3. .1..2..1. .0..3..1. .0..3..1. .3..3..1. .0..0..0. .3..1..1 %e A278729 ..2..2..2. .2..2..1. .1..1..3. .1..0..1. .2..0..0. .1..3..2. .1..2..0 %Y A278729 Cf. A278734. %K A278729 nonn %O A278729 1,1 %A A278729 _R. H. Hardin_, Nov 27 2016