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 A239504 #17 Jun 29 2021 17:37:02
%S A239504 1,1,4,5,7,7,8,9,10,10,11,11,11,12,12,12,13,13,13,13,14,14,14,14,14,
%T A239504 14,15,15,15,15,15,15,16,16,16,16,16,16,16,16,17,17,17,17,17,17,17,17,
%U A239504 17,17,17,18,18,18,18,18,18,18,18,18,18,18,18,18,19,19,19
%N A239504 Number of digits in the decimal expansion of n^10 (A008454).
%F A239504 a(n) = floor(10*log_10(n))+1 for n>0, a(0) = 1.
%F A239504 a(n) = A055642(n^10).
%e A239504 a(1) = 1, because 1^10 = 1.
%e A239504 a(2) = 4, because 2^10 = 1024.
%t A239504 Join[{1},IntegerLength[Range[80]^10]] (* _Harvey P. Dale_, Jun 29 2021 *)
%o A239504 (PARI) a(n) = #Str(n^10); \\ _Michel Marcus_, Mar 21 2014
%K A239504 nonn,base,easy
%O A239504 0,3
%A A239504 _Lorianne Kwak_, Mar 20 2014