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 A207345 #7 Jul 22 2025 20:18:45 %S A207345 25,625,1704,12292,71344,388134,2367656,13950908,79860282,473919476, %T A207345 2786796897,16214534579,95457905658,560591392760,3278996579419, %U A207345 19256876712615,113017014575263,662243340003005,3886173014048250 %N A207345 Number of nX7 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 0 and 1 1 1 vertically. %C A207345 Column 7 of A207346 %H A207345 R. H. Hardin, <a href="/A207345/b207345.txt">Table of n, a(n) for n = 1..210</a> %e A207345 Some solutions for n=4 %e A207345 ..1..0..1..0..1..0..1....1..0..1..0..1..0..0....1..1..1..0..1..0..1 %e A207345 ..0..0..1..0..0..1..0....0..1..0..1..0..0..1....0..1..0..1..0..0..1 %e A207345 ..1..1..0..1..0..0..1....0..1..0..1..0..1..0....1..0..0..1..0..1..0 %e A207345 ..0..0..1..0..1..0..0....1..0..1..0..1..0..1....1..1..1..0..1..0..1 %K A207345 nonn %O A207345 1,1 %A A207345 _R. H. Hardin_ Feb 17 2012