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 A094027 #5 Jun 13 2015 00:51:20 %S A094027 0,1,100,101,10100,10101,1010100,1010101,101010100,101010101, %T A094027 10101010100,10101010101,1010101010100,1010101010101,101010101010100, %U A094027 101010101010101,10101010101010100,10101010101010101 %N A094027 Expansion of x(1+100x)/((1-x^2)(1-100x^2)). %C A094027 The expansion of x(1+kx)/((1-x^2)(1-kx^2)) has a(n)=k^((n+1)/2)/(2(sqrt(k)-1))-(-sqrt(k))^(n+1)/(2(sqrt(k)+1))-(-1)^n/2-(k+1)/(2(k-1)) %H A094027 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,101,0,-100). %F A094027 a(n)=2^n*5^(n+1)((-1)^n/11+1/9)-(-1)^n/2-101/198 %Y A094027 Cf. A075427, A094025, A080610 (interpreted as binary), A094026. %K A094027 easy,nonn %O A094027 0,3 %A A094027 _Paul Barry_, Apr 22 2004