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 A300471 #6 Sep 04 2022 22:27:26 %S A300471 64,5536,180397,7121067,284885784,11408562672,456303004550, %T A300471 18253046515989,730219136878799,29212758892049864,1168662232086807413, %U A300471 46752555205748619684,1870345397930689285305,74823548553594183996315 %N A300471 Number of n X 7 0..1 arrays with every element equal to 0, 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. %C A300471 Column 7 of A300472. %H A300471 R. H. Hardin, <a href="/A300471/b300471.txt">Table of n, a(n) for n = 1..210</a> %e A300471 Some solutions for n=5 %e A300471 ..0..0..0..1..0..0..0. .0..0..0..0..1..0..0. .0..0..0..1..1..1..0 %e A300471 ..0..1..0..1..1..0..1. .0..1..0..1..0..1..1. .0..1..0..1..0..0..1 %e A300471 ..0..1..0..0..1..1..0. .0..1..0..0..1..0..0. .0..1..0..1..1..0..1 %e A300471 ..0..0..1..0..0..1..1. .0..0..1..0..0..1..0. .0..0..1..0..0..1..0 %e A300471 ..0..1..0..1..1..0..0. .0..1..0..1..1..0..0. .0..1..0..1..0..0..0 %Y A300471 Cf. A300472. %K A300471 nonn %O A300471 1,1 %A A300471 _R. H. Hardin_, Mar 06 2018