%I
%S 1,2,1,1,2,1,3,3,1,2,3,1,3,4,4,4,4,2,3,3,4,3,2,3,2,2,3,5,5,4,3,4,2,5,
%T 6,2,5,3,2,3,3,3,3,3,4,2,4,2,5,2,3,5,3,6,4,5,2,5,4,3,3,3,4,2,5,4,4,5,
%U 5,4,5,1,3,6,4,2,2,4,3,4,5,7,6,5,4,8,4
%N Number of distinct prime divisors of 88...887 (with n 8s).
%H Amiram Eldar, <a href="/A105248/b105248.txt">Table of n, a(n) for n = 0..199</a>
%F a(n) = A001221(A173812(n+1)).  _Michel Marcus_, Jan 27 2014
%e The number of distinct prime divisors of 87 is 2.
%e The number of distinct prime divisors of 887 is 1 (prime).
%e The number of distinct prime divisors of 8887 is 1 (prime).
%t Table[PrimeNu[(8*10^(n + 1)  17)/9], {n, 1, 50}] (* _G. C. Greubel_, May 21 2017 *)
%o a(n) = omega((8*10^(n+1)17)/9); \\ _Michel Marcus_, Jan 27 2014
%Y Cf. A104524, A104889.
%K nonn,base
%O 0,2
%A _Parthasarathy Nambi_, Apr 29 2005
%E More terms from Brian Lauer (bel136(AT)psu.edu), Feb 23 2006
%E Corrected and extended by _Michel Marcus_, Jan 27 2014
%E More terms from _Amiram Eldar_, Jan 27 2020
