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 A224487 #14 Apr 08 2013 04:12:13
%S A224487 2,4,4,6,10,39,102,44,165,96,154,446,406,714,999,1634,2698,5445,7630,
%T A224487 11670,17833,28758,46686,75178,121782,197890,319081,522734,840924
%N A224487 Least integer b > F(n) such that sum_{k=1}^n F(k)*b^{k-1} is prime, where F = A000045.
%C A224487 Conjecture: For any n > 1 we have a(n) < F(n+4); moreover, there are infinitely many integers b > F(n) such that sum_{k=1}^n F(k)*b^{k-1} is prime.
%H A224487 Zhi-Wei Sun, <a href="/A224487/b224487.txt">Table of n, a(n) for n = 2..49</a>
%e A224487 a(6) = 10 since sum_{k=0}^6 F(k)*10^{k-1} = 853211 is prime but sum_{k=0}^6 F(k)*9^{k-1} = 507556 is composite.
%t A224487 A[n_,x_]:=A[n,x]=Sum[Fibonacci[k]*x^(k-1),{k,1,n}]
%t A224487 Do[Do[Do[If[PrimeQ[A[n,s]]==True,Print[n," ",s];Goto[aa]],{s,Fibonacci[n]+1,Fibonacci[n+4]-1}];
%t A224487 Print[n," ",counterexample];Label[aa];Continue,{n,2,20}]]
%Y A224487 Cf. A000040, A000045, A220947, A217785, A218465, A217788.
%K A224487 nonn
%O A224487 2,1
%A A224487 _Zhi-Wei Sun_, Apr 08 2013