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 A241608 #9 Oct 30 2018 10:33:49 %S A241608 10,20,40,76,147,287,556,1077,2091,4057,7868,15264,29613,57445,111438, %T A241608 216184,419380,813563,1578253,3061693,5939450,11522085,22351978, %U A241608 43361147,84117349,163181309,316559417,614101361,1191310271,2311051970,4483266305 %N A241608 Number of length n+2 0..2 arrays with no consecutive three elements summing to more than 2. %H A241608 R. H. Hardin, <a href="/A241608/b241608.txt">Table of n, a(n) for n = 1..210</a> %F A241608 Empirical: a(n) = a(n-1) + a(n-2) + 2*a(n-3) - a(n-5) - a(n-6). %F A241608 Empirical g.f.: x*(10 + 10*x + 10*x^2 - 4*x^3 - 9*x^4 - 6*x^5) / (1 - x - x^2 - 2*x^3 + x^5 + x^6). - _Colin Barker_, Oct 30 2018 %e A241608 Some solutions for n=5: %e A241608 ..1....0....2....0....1....2....2....1....0....1....1....0....1....1....1....0 %e A241608 ..0....1....0....0....0....0....0....1....1....0....0....0....0....0....0....1 %e A241608 ..1....0....0....0....1....0....0....0....0....1....1....0....1....0....0....0 %e A241608 ..0....0....0....0....0....0....0....1....1....1....0....1....1....1....0....0 %e A241608 ..0....2....0....0....0....1....0....1....1....0....0....0....0....0....1....0 %e A241608 ..1....0....1....0....1....0....1....0....0....1....2....0....1....1....1....0 %e A241608 ..1....0....0....2....0....0....1....0....0....0....0....2....1....0....0....0 %Y A241608 Column 2 of A241619. %K A241608 nonn %O A241608 1,1 %A A241608 _R. H. Hardin_, Apr 26 2014