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 A278323 #4 Nov 18 2016 06:43:08 %S A278323 21,1492,51229,1548002,43798840,1133034160,26606146271,577253086055, %T A278323 11856994168275,234252250004719,4462457602929707,81437338008292870, %U A278323 1411665474225016752,23098384621606953307,355699829714059120732 %N A278323 Number of nX6 0..1 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes. %C A278323 Column 6 of A278325. %H A278323 R. H. Hardin, <a href="/A278323/b278323.txt">Table of n, a(n) for n = 1..150</a> %e A278323 Some solutions for n=3 %e A278323 ..0..1..0..1..1..0. .0..1..0..1..0..1. .0..0..0..1..1..1. .0..1..0..1..1..1 %e A278323 ..1..0..1..0..1..1. .0..1..1..0..1..0. .0..1..1..1..1..1. .1..0..0..1..0..0 %e A278323 ..1..1..0..0..1..0. .1..0..1..1..0..1. .1..1..0..1..1..0. .1..0..0..1..0..1 %Y A278323 Cf. A278325. %K A278323 nonn %O A278323 1,1 %A A278323 _R. H. Hardin_, Nov 18 2016