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 A278624 #4 Nov 24 2016 08:44:18 %S A278624 126,8518,439446,21121532,978005050,43853346948,1892563134910, %T A278624 77595353266488,2984253200734849,106802443365088678, %U A278624 3546576756421791553,109349563224002187119,3138905373936577741625,84191222241450755762521 %N A278624 Number of nX5 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly one mistake. %C A278624 Column 5 of A278627. %H A278624 R. H. Hardin, <a href="/A278624/b278624.txt">Table of n, a(n) for n = 1..101</a> %e A278624 Some solutions for n=2 %e A278624 ..1..1..0..2..2. .0..0..1..1..0. .1..1..1..2..1. .0..2..2..2..0 %e A278624 ..2..0..1..1..1. .1..0..1..0..1. .2..0..0..1..0. .2..0..0..0..0 %Y A278624 Cf. A278627. %K A278624 nonn %O A278624 1,1 %A A278624 _R. H. Hardin_, Nov 24 2016