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 A203377 #7 Jul 22 2025 17:11:31 %S A203377 8748,323852,12301020,471988172,18189909480,702420750924, %T A203377 27149753088792,1049837466171436,40603753889665632, %U A203377 1570549319417597656,60751409051086135560,2350012855527394133452,90905131505907584858388 %N A203377 Number of (n+1)X8 0..1 arrays with every 2X2 subblock having equal diagonal elements or equal antidiagonal elements. %C A203377 Column 7 of A203378 %H A203377 R. H. Hardin, <a href="/A203377/b203377.txt">Table of n, a(n) for n = 1..210</a> %F A203377 Empirical: a(n) = 105*a(n-1) -4473*a(n-2) +105654*a(n-3) -1580037*a(n-4) +16082595*a(n-5) -116408090*a(n-6) +616031475*a(n-7) -2425718097*a(n-8) +7181467374*a(n-9) -16063429749*a(n-10) +27150592284*a(n-11) -34525830041*a(n-12) +32730104655*a(n-13) -22785383754*a(n-14) +11380763892*a(n-15) -3932260752*a(n-16) +884206944*a(n-17) -115250048*a(n-18) +6527616*a(n-19) %e A203377 Some solutions for n=4 %e A203377 ..1..1..1..1..0..0..1..1....0..0..1..0..0..0..1..0....1..0..1..0..1..1..1..1 %e A203377 ..1..1..0..1..1..0..0..1....1..0..0..1..0..0..0..1....0..1..0..1..0..1..0..1 %e A203377 ..1..1..1..0..1..1..0..0....0..1..0..0..1..0..1..1....0..0..1..0..0..0..1..0 %e A203377 ..0..1..1..1..1..0..1..0....0..0..1..0..0..0..0..1....0..0..0..1..0..0..0..0 %e A203377 ..0..0..1..1..0..1..0..0....1..0..0..1..0..1..0..0....0..1..0..0..0..0..1..0 %K A203377 nonn %O A203377 1,1 %A A203377 _R. H. Hardin_ Dec 31 2011