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 A105973 #21 Jan 14 2024 13:28:30
%S A105973 1,1,1,3,1,2,2,1,1,5,2,3,3,2,1,4,2,2,3,2,3,6,3,2,2,4,3,8,3,5,3,3,4,5,
%T A105973 4,4,6,4,2,4,4,5,4,6,5,7,4,5,4,2,1,5,3,2,5,4,5,4,4,3,4,2,4,8,4,5,2,5,
%U A105973 5,5,1,2,6,5,4,5,1,2,7,3,4,9,6,7,7,4,4,3,4,5,6,6,7,5,4,3,5,5,2,6
%N A105973 Number of distinct prime divisors of 88...883 (with n 8's).
%H A105973 Amiram Eldar, <a href="/A105973/b105973.txt">Table of n, a(n) for n = 0..201</a>
%F A105973 a(n) = A001221(A173811(n+1)). - _Michel Marcus_, Jan 27 2014
%e A105973 The number of distinct prime divisors of 83 is 1 (prime).
%e A105973 The number of distinct prime divisors of 883 is 1 (prime).
%e A105973 The number of distinct prime divisors of 8883 is 3.
%t A105973 Table[PrimeNu[FromDigits[PadLeft[{3},n,8]]],{n,100}] (* _Harvey P. Dale_, Mar 08 2015 *)
%o A105973 (PARI) a(n) = omega((8*10^(n+1)-53)/9); \\ _Michel Marcus_, Jan 27 2014
%Y A105973 Cf. A104660, A104518, A104660.
%K A105973 nonn,base
%O A105973 0,4
%A A105973 _Parthasarathy Nambi_, Apr 28 2005