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 A231520 #7 Jul 23 2025 06:33:35 %S A231520 12,342,4665,70462,1031105,15000701,219937967,3222629836,47159743290, %T A231520 690399979855,10108622083346,147993608472149,2166661772771563, %U A231520 31720960292577983,464409247083163776,6799146031063407846 %N A231520 Number of nX5 0..1 arrays with no element less than a strict majority of its horizontal, diagonal and antidiagonal neighbors. %C A231520 Column 5 of A231523 %H A231520 R. H. Hardin, <a href="/A231520/b231520.txt">Table of n, a(n) for n = 1..210</a> %H A231520 R. H. Hardin, <a href="/A231520/a231520.txt">Empirical recurrence of order 70</a> %F A231520 Empirical recurrence of order 70 (see link above) %e A231520 Some solutions for n=4 %e A231520 ..0..1..0..0..0....0..0..0..1..0....0..1..0..0..0....1..1..0..0..0 %e A231520 ..1..0..1..1..1....0..0..0..0..1....0..0..0..1..1....0..0..1..1..0 %e A231520 ..0..0..0..1..1....0..1..0..0..0....0..0..0..1..1....1..0..0..0..1 %e A231520 ..0..0..0..1..1....0..0..1..1..1....1..0..0..1..1....1..1..0..1..1 %K A231520 nonn %O A231520 1,1 %A A231520 _R. H. Hardin_, Nov 10 2013