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 A183316 #7 Jul 22 2025 08:48:40 %S A183316 8,27,124,480,1975,7833,31428,125103,498825,1985956,7906167,31469417, %T A183316 125232138,498389829,1983161935,7891800110,31402125248,124956937711, %U A183316 497214816218,1978508290987,7872687718931,31326612697486,124652113265387 %N A183316 Number of nX4 binary arrays with an element zero only if there are an even number of ones to its left and an even number of ones above it. %C A183316 Column 4 of A183322 %H A183316 R. H. Hardin, <a href="/A183316/b183316.txt">Table of n, a(n) for n = 1..200</a> %F A183316 Empirical: a(n)=a(n-1)+23*a(n-2)-10*a(n-3)-180*a(n-4)+34*a(n-5)+630*a(n-6)-63*a(n-7)-1081*a(n-8)+73*a(n-9)+914*a(n-10)-50*a(n-11)-352*a(n-12)+14*a(n-13)+47*a(n-14)+a(n-15)-a(n-16) %e A183316 Some solutions for 5X4 %e A183316 ..0..1..1..0....0..0..0..0....0..1..1..0....0..0..0..1....0..1..1..1 %e A183316 ..0..1..1..0....0..0..0..0....0..1..1..0....0..1..1..1....0..1..1..1 %e A183316 ..1..1..0..0....0..1..1..1....0..0..0..0....0..1..1..0....1..1..0..1 %e A183316 ..1..1..1..1....0..1..1..1....0..0..0..0....0..0..0..0....1..1..0..1 %e A183316 ..0..0..1..1....1..1..1..1....0..0..1..1....0..1..1..0....1..1..1..1 %K A183316 nonn %O A183316 1,1 %A A183316 _R. H. Hardin_ Jan 03 2011