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 A241609 #8 Oct 30 2018 10:33:38 %S A241609 20,50,125,295,711,1730,4175,10077,24377,58928,142396,344201,832011, %T A241609 2010980,4860690,11748840,28397936,68640170,165909570,401018224, %U A241609 969296175,2342874854,5662936565,13687818660,33084669767,79968578621 %N A241609 Number of length n+2 0..3 arrays with no consecutive three elements summing to more than 3. %H A241609 R. H. Hardin, <a href="/A241609/b241609.txt">Table of n, a(n) for n = 1..210</a> %F A241609 Empirical: a(n) = 2*a(n-1) + 4*a(n-3) - 3*a(n-4) - a(n-5) - 3*a(n-6) + 2*a(n-7) + a(n-9) - a(n-10). %F A241609 Empirical g.f.: x*(20 + 10*x + 25*x^2 - 35*x^3 - 19*x^4 - 22*x^5 + 20*x^6 + 3*x^7 + 6*x^8 - 10*x^9) / ((1 - x)*(1 - x - x^2 - 5*x^3 - 2*x^4 - x^5 + 2*x^6 - x^9)). - _Colin Barker_, Oct 30 2018 %e A241609 Some solutions for n=5: %e A241609 ..1....2....3....2....1....0....3....0....1....1....1....1....1....3....2....0 %e A241609 ..0....1....0....1....2....1....0....0....1....1....0....1....1....0....0....1 %e A241609 ..1....0....0....0....0....2....0....0....0....0....1....0....1....0....0....1 %e A241609 ..0....0....1....0....0....0....1....0....1....2....2....0....1....2....3....1 %e A241609 ..0....0....2....1....1....1....1....0....1....1....0....1....0....1....0....0 %e A241609 ..0....2....0....2....2....1....1....0....0....0....0....0....1....0....0....0 %e A241609 ..3....1....1....0....0....1....0....1....1....2....0....0....1....2....1....3 %Y A241609 Column 3 of A241619. %K A241609 nonn %O A241609 1,1 %A A241609 _R. H. Hardin_, Apr 26 2014