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 A208082 #7 Jul 22 2025 21:09:31 %S A208082 40,1600,27880,572040,11204720,223058440,4412968520,87523832240, %T A208082 1734118456440,34372785484040,681198922297440,13500986230325880, %U A208082 267573654641996120,5303065945847377120,105101332133461259960 %N A208082 Number of 7Xn 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 0 and 0 1 0 vertically. %C A208082 Row 7 of A208078 %H A208082 R. H. Hardin, <a href="/A208082/b208082.txt">Table of n, a(n) for n = 1..210</a> %F A208082 Empirical: a(n) = 8*a(n-1) +240*a(n-2) +212*a(n-3) -6470*a(n-4) -2816*a(n-5) +58646*a(n-6) +3528*a(n-7) -215345*a(n-8) +36778*a(n-9) +305644*a(n-10) -78492*a(n-11) -174713*a(n-12) +38956*a(n-13) +42650*a(n-14) -5016*a(n-15) -4246*a(n-16) +194*a(n-17) +156*a(n-18) -a(n-20) %e A208082 Some solutions for n=4 %e A208082 ..0..1..1..1....1..0..1..1....1..1..1..1....0..1..1..0....1..0..1..0 %e A208082 ..0..1..0..1....0..1..0..0....1..0..1..0....0..1..0..0....1..0..1..1 %e A208082 ..1..0..1..1....0..1..0..0....1..1..1..0....1..1..1..1....0..1..0..1 %e A208082 ..1..0..1..1....1..1..1..1....1..1..1..1....1..0..1..1....1..1..0..0 %e A208082 ..1..1..0..0....1..1..1..1....1..0..1..1....1..0..1..0....1..0..1..1 %e A208082 ..1..1..1..1....1..0..1..0....0..1..0..1....0..1..0..1....0..1..1..1 %e A208082 ..1..1..1..1....1..0..1..1....0..1..0..1....1..1..0..1....1..1..1..0 %K A208082 nonn %O A208082 1,1 %A A208082 _R. H. Hardin_ Feb 23 2012