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 A207862 #7 Jul 22 2025 20:54:20 %S A207862 42,1764,14406,117649,1737981,25674489,298294290,3465676900, %T A207862 44249929850,564985239025,6946276116395,85401792033481, %U A207862 1066016616909398,13306411967110084,165079309220454794,2047973443183647529 %N A207862 Number of 7Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 0 and 1 0 1 vertically. %C A207862 Row 7 of A207858 %H A207862 R. H. Hardin, <a href="/A207862/b207862.txt">Table of n, a(n) for n = 1..210</a> %e A207862 Some solutions for n=4 %e A207862 ..0..1..1..0....0..0..1..1....0..0..1..1....0..0..1..1....0..0..1..1 %e A207862 ..0..0..1..1....0..1..1..0....0..1..1..1....0..0..1..1....0..1..1..1 %e A207862 ..1..0..0..1....1..1..0..0....0..1..1..0....1..1..1..1....1..1..1..1 %e A207862 ..1..0..0..1....1..0..0..1....1..1..0..0....1..1..1..0....1..1..1..0 %e A207862 ..0..0..1..1....1..0..1..1....1..1..0..0....0..1..1..0....0..1..1..0 %e A207862 ..0..1..1..1....1..0..1..1....1..0..0..1....0..1..1..1....0..1..1..1 %e A207862 ..1..1..1..0....0..0..1..1....0..0..1..1....1..1..0..1....0..1..1..1 %K A207862 nonn %O A207862 1,1 %A A207862 _R. H. Hardin_ Feb 21 2012