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 A144607 #4 May 30 2025 13:39:07 %S A144607 0,0,1,0,1,0,1,0,1,0,0,1,0,1,0,1,0,1,0,1,0,0,1,0,1,0,1,0,1,0,0,1,0,1, %T A144607 0,1,0,1,0,1,0,0,1,0,1,0,1,0,1,0,0,1,0,1,0,1,0,1,0,1,0,0,1,0,1,0,1,0, %U A144607 1,0,0,1,0,1,0,1,0,1,0,1,0,0,1,0,1,0,1,0,1,0,0,1,0,1,0,1,0,1,0,1,0,0,1,0,1 %N A144607 Christoffel word of slope 9/11. %F A144607 a(n) = a(n-20). - _R. J. Mathar_, May 30 2025 %F A144607 G.f.: -x^2*(1+x^2+x^4+x^6+x^9+x^11+x^13+x^15+x^17) / ( (x-1)*(1+x^4+x^3+x^2+x)*(1+x)*(1-x+x^2-x^3+x^4)*(1+x^2)*(x^8-x^6+x^4-x^2+1) ). - _R. J. Mathar_, May 30 2025 %Y A144607 See A144595 for further details. %K A144607 nonn,easy %O A144607 0,1 %A A144607 _N. J. A. Sloane_, Jan 13 2009