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 A281806 #4 Jan 30 2017 10:45:13 %S A281806 0,87,865,8354,71445,575062,4480480,33526931,246399359,1768719496, %T A281806 12506519769,87220471545,600957372469,4100864353926,27733540904781, %U A281806 186134535819880,1240811810649533,8221127809327654,54176483907555951 %N A281806 Number of 5Xn 0..1 arrays with no element unequal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards. %C A281806 Row 5 of A281802. %H A281806 R. H. Hardin, <a href="/A281806/b281806.txt">Table of n, a(n) for n = 1..210</a> %e A281806 Some solutions for n=4 %e A281806 ..0..1..1..0. .0..1..0..0. .0..0..1..1. .0..0..0..0. .0..0..1..0 %e A281806 ..1..1..0..1. .1..0..0..0. .1..1..1..1. .1..0..0..0. .0..1..0..1 %e A281806 ..0..0..1..1. .1..1..1..1. .1..1..1..1. .0..1..0..1. .1..0..1..0 %e A281806 ..0..0..1..1. .1..1..1..0. .1..1..1..1. .1..0..1..0. .1..1..0..1 %e A281806 ..1..1..0..0. .1..1..0..0. .1..1..0..1. .1..1..0..1. .0..0..0..0 %Y A281806 Cf. A281802. %K A281806 nonn %O A281806 1,2 %A A281806 _R. H. Hardin_, Jan 30 2017