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 A181250 #5 May 25 2024 21:36:35 %S A181250 128,11772,1169792,114142368,11185495872,1095020802848, %T A181250 107224417436160,10498818149889952,1027999596778673856, %U A181250 100657027683287334528,9855884014448812881664,965043721129265059674752 %N A181250 Number of n X 7 binary matrices with no 2 X 2 block having four 1's. %C A181250 Column 7 of A181253. %H A181250 R. H. Hardin, <a href="/A181250/b181250.txt">Table of n, a(n) for n=1..200</a> %F A181250 Empirical: a(n)=68*a(n-1)+3106*a(n-2)-10300*a(n-3)-731184*a(n-4)+3930848*a(n-5)+47046600*a(n-6)-471525808*a(n-7)+1012118640*a(n-8)+2396096576*a(n-9)-9445394304*a(n-10)-4382776896*a(n-11)+29415041536*a(n-12)+8676097024*a(n-13)-36065068032*a(n-14)-14871987200*a(n-15)+10138337280*a(n-16)+2907136000*a(n-17)-1119682560*a(n-18). %Y A181250 Cf. A181253. %K A181250 nonn %O A181250 1,1 %A A181250 _R. H. Hardin_, Oct 10 2010