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 A072354 #31 Jul 19 2025 23:05:33
%S A072354 1,7,12,17,21,26,31,36,40,45,50,55,60,64,69,74,79,84,88,93,98,103,107,
%T A072354 112,117,122,127,131,136,141,146,151,155,160,165,170,174,179,184,189,
%U A072354 194,198,203,208,213,217,222,227,232,237
%N A072354 a(n)-th Fibonacci number is the smallest Fibonacci number containing n digits.
%H A072354 Harry J. Smith, <a href="/A072354/b072354.txt">Table of n, a(n) for n = 1..20899</a>
%F A072354 For n>1, a(n) = A072353(n-1) + 1. - _Michel Marcus_, Jun 01 2014
%F A072354 For n>1, a(n) = ceiling(n*log(10)/log(phi)-log(20)/(2*log(phi))), where phi=(1+sqrt(5))/2, the golden ratio. - _Hans J. H. Tuenter_, Jul 13 2025
%e A072354 a(3) = 12 as the 12th Fibonacci number is the smallest Fibonacci number with 3 digits.
%t A072354 Flatten[Table[Position[IntegerLength[Fibonacci[Range[250]]],n,{1},1],{n,50}]] (* _Harvey P. Dale_, Dec 22 2015 *)
%o A072354 (PARI) a(n)={my(k=1); while(logint(fibonacci(k),10)<n-1, k++); k} \\ _Harry J. Smith_, Nov 29 2008
%Y A072354 Cf. A001622, A105700, A105702, A105703, A105704, A105705, A105706, A105707, A105708, A105709.
%K A072354 base,nonn
%O A072354 1,2
%A A072354 _Shyam Sunder Gupta_, Jul 18 2002