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 A164018 #9 Jun 04 2018 16:30:12
%S A164018 0,6,7,11,12,16,17,20,21,25,26,30,31,35,36,39,40,44,45,49,50,54,55,59,
%T A164018 60,63,64,68,69,73,74,78,79,83,84,87,88,92,93,97,98,102,103,106,107,
%U A164018 111,112,116,117,121,122,126,127,130,131,135,136,140,141,145
%N A164018 The index values of the smallest and the largest n-digit Fibonacci numbers.
%C A164018 = A072354 + A072353 [From _Parthasarathy Nambi_, Sep 14 2009]
%H A164018 Harvey P. Dale, <a href="/A164018/b164018.txt">Table of n, a(n) for n = 0..999</a>
%e A164018 The index value of the smallest ten digit Fibonacci number is 45. The index value of the largest ten digit Fibonacci number is 49.
%t A164018 Drop[Flatten[{#-1,#}&/@Flatten[Table[Position[IntegerLength[Fibonacci[ Range[250]]],n,1,1],{n,50}]]],{2}](* _Harvey P. Dale_, Jun 04 2018 *)
%Y A164018 Cf. A000045
%K A164018 base,nonn
%O A164018 0,2
%A A164018 _Parthasarathy Nambi_, Aug 07 2009
%E A164018 More terms from _Harvey P. Dale_, Jun 04 2018