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 A105068 #13 Jan 25 2020 06:19:03
%S A105068 1,1,1,2,2,2,2,2,3,2,2,2,3,2,4,4,1,4,5,4,2,2,4,2,2,3,4,3,4,3,6,4,3,2,
%T A105068 4,4,5,3,5,5,4,5,7,4,5,4,7,5,4,4,5,4,3,2,4,4,2,5,5,4,4,3,3,4,2,3,5,5,
%U A105068 6,5,4,3,3,5,6,5,5,4,7,4,3,5,4,5,5,2,6
%N A105068 Number of distinct prime divisors of 10^n - 3.
%H A105068 Amiram Eldar, <a href="/A105068/b105068.txt">Table of n, a(n) for n = 1..121</a>
%F A105068 a(n) = A001221(A173833(n)). - _Amiram Eldar_, Jan 25 2020
%e A105068 If n = 1, 2 or 3, then 10^n - 3 is prime and thus the first three terms are 1.
%t A105068 Table[Length[FactorInteger[10^n - 3]], {n, 1, 50}] (* _Stefan Steinerberger_, Feb 21 2006 *)
%Y A105068 Cf. A001221, A173833.
%K A105068 nonn
%O A105068 1,4
%A A105068 _Parthasarathy Nambi_, Apr 05 2005
%E A105068 More terms from _Stefan Steinerberger_, Feb 21 2006
%E A105068 More terms from _Amiram Eldar_, Jan 25 2020