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 A060522 #10 Nov 28 2022 21:48:24 %S A060522 10,100,378,2030,9484,46746,225654,1098136,5327258,25875154,125619088, %T A060522 609970274,2961628194,14380186660,69822244298,339019686614, %U A060522 1646096608476,7992561729954,38807580840854,188428757462264,914908750899146,4442305123352810,21569445781449640 %N A060522 Number of 4 X n grids of black and white cells, no 3 of same color vertically or horizontally contiguous. %C A060522 The 1 X n, 2 X n, 3 X n versions satisfied recurrence relations of degrees 2, 3, 4 respectively, but I have done quite a lot of LLL work and failed to find a degree-5 relation for this one. %H A060522 R. H. Hardin, <a href="/A060522/b060522.txt">Table of n, a(n) for n = 1..212</a> %H A060522 Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a060/A060522.java">Java program</a> (github) %F A060522 Empirical: a(n)=3*a(n-1)+12*a(n-2)+a(n-3)-58*a(n-4)-115*a(n-5)+83*a(n-6)+312*a(n-7)+120*a(n-8)-336*a(n-9)-348*a(n-10)+420*a(n-11)+104*a(n-12)-194*a(n-13)+43*a(n-14)+35*a(n-15)-42*a(n-16)-3*a(n-17)+14*a(n-18)-a(n-19)-a(n-20) - R. H. Hardin, Jan 01 2012 %K A060522 nonn %O A060522 1,1 %A A060522 Tom Womack (tom(AT)womack.net)