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 A181251 #5 Jun 22 2022 11:33:46 %S A181251 256,44631,8515337,1590466304,298561305103,55979092539545, %T A181251 10498818149889952,1968910887183791359,369248337357375835969, %U A181251 69248348058920729348864,12986755671559657328386775 %N A181251 Number of n X 8 binary matrices with no 2 X 2 block having four 1's. %C A181251 Column 8 of A181253. %H A181251 R. H. Hardin, <a href="/A181251/b181251.txt">Table of n, a(n) for n=1..200</a> %F A181251 Empirical: a(n)=113*a(n-1)+13879*a(n-2)+91506*a(n-3)-13567062*a(n-4)-45766270*a(n-5)+5948333641*a(n-6)-25692714697*a(n-7)-932093986319*a(n-8)+9749317949468*a(n-9)+6293344318720*a(n-10)-400364584466276*a(n-11)+544975615003201*a(n-12)+8011657063605359*a(n-13)-12237642139437047*a(n-14)-98976024373360414*a(n-15)+87321080164809042*a(n-16)+743714645681446194*a(n-17)-21941742884172873*a(n-18)-2838216189512832023*a(n-19)-1559534908222727729*a(n-20)+4451110188283146640*a(n-21)+3110756142589939204*a(n-22)-3806251587192837456*a(n-23)-2258950594106495040*a(n-24)+1998716044109621760*a(n-25)+565195437997056000*a(n-26)-541032812384256000*a(n-27)+28184753405952000*a(n-28)+19493777571840000*a(n-29). %Y A181251 Cf. A181253. %K A181251 nonn %O A181251 1,1 %A A181251 _R. H. Hardin_, Oct 10 2010