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 A297400 #4 Dec 29 2017 11:01:31 %S A297400 1,178,963,3924,74736,640562,4279111,46261441,428200086,3465586864, %T A297400 32328050104,296748190460,2574529121380,23200388627087, %U A297400 210159449303417,1865437561436124,16702908801335717,150242351184841826 %N A297400 Number of 7Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 neighboring 1. %C A297400 Row 7 of A297395. %H A297400 R. H. Hardin, <a href="/A297400/b297400.txt">Table of n, a(n) for n = 1..210</a> %H A297400 R. H. Hardin, <a href="/A297400/a297400.txt"> Empirical recurrence of order 69</a> %F A297400 Empirical recurrence of order 69 (see link above) %e A297400 Some solutions for n=5 %e A297400 ..1..0..0..1..1. .1..0..0..1..1. .0..1..0..0..0. .1..1..0..1..0 %e A297400 ..0..1..0..0..0. .0..1..0..0..0. .0..0..1..0..0. .0..0..0..0..1 %e A297400 ..0..0..0..1..1. .0..1..0..1..1. .0..0..1..0..0. .0..1..1..0..0 %e A297400 ..1..0..0..0..0. .1..0..0..0..0. .0..1..0..0..0. .0..0..0..0..1 %e A297400 ..0..1..0..0..0. .0..0..0..0..0. .0..0..0..0..0. .0..0..0..1..0 %e A297400 ..0..0..0..0..0. .0..0..1..0..0. .0..1..1..0..0. .0..1..0..0..0 %e A297400 ..0..0..0..1..1. .0..0..0..1..0. .0..0..0..0..0. .0..0..1..0..0 %Y A297400 Cf. A297395. %K A297400 nonn %O A297400 1,2 %A A297400 _R. H. Hardin_, Dec 29 2017