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 A202738 #7 Jul 22 2025 16:48:29 %S A202738 2,22,140,838,5092,29680,183220,1061814,6630116,39048472,242647660, %T A202738 1438692856,8910239756,53090781836,327214611580,1954347351734, %U A202738 11998820896676,71771002591048,439163289580348,2629051988484048 %N A202738 Number of nX4 0..1 arrays with row sums equal and column sums unequal to adjacent columns. %C A202738 Column 4 of A202742 %H A202738 R. H. Hardin, <a href="/A202738/b202738.txt">Table of n, a(n) for n = 1..74</a> %e A202738 Some solutions for n=5 %e A202738 ..0..1..1..0....1..0..1..0....0..1..0..1....1..1..0..0....1..1..0..0 %e A202738 ..0..0..1..1....0..0..1..1....1..0..1..0....0..1..1..0....1..0..0..1 %e A202738 ..0..1..0..1....1..0..1..0....0..1..1..0....0..1..1..0....1..0..0..1 %e A202738 ..0..1..0..1....1..0..1..0....0..1..1..0....1..0..0..1....1..0..1..0 %e A202738 ..1..0..0..1....0..1..0..1....0..0..1..1....1..1..0..0....0..1..0..1 %K A202738 nonn %O A202738 1,1 %A A202738 _R. H. Hardin_ Dec 23 2011