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A034888 Number of digits in 3^n. 9

%I

%S 1,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11,12,12,13,13,14,

%T 14,15,15,16,16,17,17,18,18,19,19,20,20,21,21,21,22,22,23,23,24,24,25,

%U 25,26,26,27,27,28,28,29,29,30,30,31,31,32,32,32,33,33

%N Number of digits in 3^n.

%H G. C. Greubel, <a href="/A034888/b034888.txt">Table of n, a(n) for n = 0..10000</a>

%F a(n) = floor(n*log(3)/log(10)) + 1. E.g., a(10)=5 because 3^10 = 59049 and floor(10*log(3)/log(10)) + 1 = 4 + 1 = 5. - _Jaap Spies_, Dec 15 2003

%F a(n) = A055642(3^n) = A055642(A000244(n)). - _Michel Marcus_, Jun 23 2015

%p seq(floor(n*ln(3)/ln(10))+1, n=0..100);

%t Table[Length[IntegerDigits[3^n]], {n, 0, 100}] (* _T. D. Noe_, Mar 20 2012 *)

%t IntegerLength[3^Range[0,70]] (* _Harvey P. Dale_, Jan 28 2015 *)

%o (PARI) a(n)=#Str(3^n) \\ _Charles R Greathouse IV_, Jul 03 2013

%o (MAGMA) [#Intseq(3^n): n in [0..100] ]; // _Vincenzo Librandi_, Jun 23 2015

%Y Cf. A000244 (powers of 3), A055642 (number of digits of n).

%K nonn,base,easy

%O 0,4

%A _N. J. A. Sloane_

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Last modified November 23 21:51 EST 2020. Contains 338603 sequences. (Running on oeis4.)