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 A181241 #5 Jul 22 2025 08:38:30 %S A181241 64,2258,85126,3185462,119310334,4468252414,167341334542, %T A181241 6267120468434,234710735573170,8790181730741270,329202219837957230, %U A181241 12328994417789802954,461734746019197769254,17292486998904958867138 %N A181241 Number of nX6 binary matrices with no 2X2 circuit having pattern 0101 in any orientation. %C A181241 Column 6 of A181245 %H A181241 R. H. Hardin, <a href="/A181241/b181241.txt">Table of n, a(n) for n=1..200</a> %F A181241 Empirical: a(n)=36*a(n-1)+120*a(n-2)-2391*a(n-3)-3905*a(n-4)+50702*a(n-5)+27152*a(n-6)-396016*a(n-7)+154999*a(n-8)+751787*a(n-9)-499260*a(n-10)-410368*a(n-11)+355981*a(n-12)+38077*a(n-13)-70276*a(n-14)+6203*a(n-15)+3386*a(n-16)-622*a(n-17)+28*a(n-18) %K A181241 nonn %O A181241 1,1 %A A181241 _R. H. Hardin_ Oct 10 2010