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 A026390 #14 Dec 29 2014 11:37:54 %S A026390 2,5,11,20,35,59,98,161,263,428,695,1127,1826,2957,4787,7748,12539, %T A026390 20291,32834,53129,85967,139100,225071,364175,589250,953429,1542683, %U A026390 2496116,4038803,6534923,10573730 %N A026390 Expansion of (2 + x + x^2)/((1 - x)*(1 - x - x^2)). %F A026390 a(n) = A022086(n+3) - 4. %t A026390 Fibonacci[Range[3,5!]]*3-4 (* _Vladimir Joseph Stephan Orlovsky_, Nov 23 2010 *) %o A026390 (PARI) Vec((2+x+x^2)/((1-x)*(1-x-x^2))+O(x^99)) \\ _Charles R Greathouse IV_, Sep 27 2012 %Y A026390 Cf. A022086. %K A026390 nonn,easy %O A026390 0,1 %A A026390 _N. J. A. Sloane_