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 A020911 #14 Sep 08 2022 08:44:45
%S A020911 1,1,1,2,2,2,3,3,4,4,5,5,5,6,6,7,7,8,8,9,9,9,10,10,11,11,12,12,12,13,
%T A020911 13,14,14,15,15,16,16,16,17,17,18,18,19,19,19,20,20,21,21,22,22,23,23,
%U A020911 23,24,24,25,25,26,26,26,27,27,28,28,29,29,30,30,30
%N A020911 Number of digits in the base 3 representation of n-th Fibonacci number.
%F A020911 a(n) = A081604(A000045(n)). - _Andrew Howroyd_, Jan 01 2020
%t A020911 IntegerLength[Fibonacci[Range[50]],3] (* _Harvey P. Dale_, Aug 13 2018 *)
%o A020911 (PARI) a(n)={1 + logint(fibonacci(n), 3)} \\ _Andrew Howroyd_, Jan 01 2020
%o A020911 (Magma) [#Intseq(Fibonacci(n),3):n in [1..70]]; // _Marius A. Burtea_, Jan 02 2020
%Y A020911 Cf. A000045 (Fibonacci numbers), A081604 (base-3 digits of n).
%K A020911 nonn,base
%O A020911 1,4
%A A020911 _Clark Kimberling_
%E A020911 Offset corrected and terms a(50) and beyond from _Andrew Howroyd_, Jan 01 2020