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 A232049 #6 Jul 23 2025 06:50:19 %S A232049 8,21,80,318,1315,5364,21680,87452,352931,1425261,5757064,23253889, %T A232049 93921193,379334811,1532086339,6187939435,24992490166,100942222266, %U A232049 407695589939,1646641727295,6650621491464,26861196902537,108489696252447 %N A232049 Number of 3Xn 0..1 arrays with no element less than a strict majority of its horizontal and antidiagonal neighbors. %C A232049 Row 3 of A232047 %H A232049 R. H. Hardin, <a href="/A232049/b232049.txt">Table of n, a(n) for n = 1..210</a> %F A232049 Empirical: a(n) = 8*a(n-1) -27*a(n-2) +64*a(n-3) -104*a(n-4) +124*a(n-5) -102*a(n-6) +34*a(n-7) +10*a(n-8) -34*a(n-9) +19*a(n-10) -2*a(n-11) +a(n-12) +10*a(n-13) -2*a(n-14) -2*a(n-15) for n>18 %e A232049 Some solutions for n=7 %e A232049 ..0..0..0..0..0..0..0....0..0..0..1..1..1..1....1..0..0..0..0..0..1 %e A232049 ..1..0..0..1..0..0..1....1..0..0..0..1..0..0....0..0..0..0..0..1..0 %e A232049 ..1..1..1..0..0..1..1....1..1..0..0..0..0..1....0..0..1..1..1..0..0 %K A232049 nonn %O A232049 1,1 %A A232049 _R. H. Hardin_, Nov 17 2013