A020911 - OEIS

%I #14 Sep 08 2022 08:44:45

%S 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 13,14,14,15,15,16,16,16,17,17,18,18,19,19,19,20,20,21,21,22,22,23,23,

%U 23,24,24,25,25,26,26,26,27,27,28,28,29,29,30,30,30

%N Number of digits in the base 3 representation of n-th Fibonacci number.

%F a(n) = A081604(A000045(n)). - _Andrew Howroyd_, Jan 01 2020

%t IntegerLength[Fibonacci[Range[50]],3] (* _Harvey P. Dale_, Aug 13 2018 *)

%o (PARI) a(n)={1 + logint(fibonacci(n), 3)} \\ _Andrew Howroyd_, Jan 01 2020

%o (Magma) [#Intseq(Fibonacci(n),3):n in [1..70]]; // _Marius A. Burtea_, Jan 02 2020

%Y Cf. A000045 (Fibonacci numbers), A081604 (base-3 digits of n).

%K nonn,base

%O 1,4

%A _Clark Kimberling_

%E Offset corrected and terms a(50) and beyond from _Andrew Howroyd_, Jan 01 2020