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 A125898 #10 Nov 21 2013 12:49:01
%S A125898 1,3,7,13,26,51,98,190,367,708,1364,2630,5071,9775,18841,36318,70007,
%T A125898 134942,260110,501380,966441,1862874,3590806,6921503,13341626,
%U A125898 25716810,49570746,95550687,184179871,355018115,684319420,1319068095,2542585503
%N A125898 Floor((quadronacci ratio)^n).
%e A125898 Quadronacci ratio is root 1.92756... (A086088) of polynomial x^4-x^3-x^2-x-1.
%t A125898 With[{c=x/.FindRoot[x^4-x^3-x^2-x-1==0,{x,1.9}, WorkingPrecision->100]}, Floor[c^Range[40]]] (* _Harvey P. Dale_, Mar 05 2012 *)
%Y A125898 Cf. A125890-A125899.
%K A125898 nonn
%O A125898 1,2
%A A125898 _Artur Jasinski_, Dec 13 2006