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 A183448 #7 Jun 02 2025 03:17:29 %S A183448 1,121,553,2399,34867,257733,1744887,16192521,132651622,1038281076, %T A183448 8774615462,72803921204,594525068675,4940133605905,40989589283304, %U A183448 338552166728150,2806660250827517,23275769947149983,192804453727767520 %N A183448 Number of nX7 binary arrays with every 1 having exactly two king-move neighbors equal to 1. %C A183448 Column 7 of A183450 %H A183448 R. H. Hardin, <a href="/A183448/b183448.txt">Table of n, a(n) for n = 1..232</a> %e A183448 Some solutions for 5X7 %e A183448 ..0..1..1..0..0..0..0....0..0..0..0..1..0..0....0..1..1..0..1..0..0 %e A183448 ..1..0..0..1..0..0..0....0..0..0..1..1..0..0....0..0..1..0..1..1..0 %e A183448 ..1..0..1..0..0..0..0....0..0..0..0..0..0..0....1..0..0..0..0..0..0 %e A183448 ..0..1..0..0..1..0..0....0..0..0..0..0..1..1....1..1..0..0..1..1..0 %e A183448 ..0..0..0..1..1..0..0....0..0..0..0..0..1..0....0..0..0..0..0..1..0 %K A183448 nonn %O A183448 1,2 %A A183448 _R. H. Hardin_ Jan 04 2011