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%I #11 Jan 27 2020 08:26:39
%S 1,2,1,2,3,2,2,4,1,3,2,3,2,2,2,2,3,3,1,5,4,4,4,7,1,4,2,5,3,3,3,3,3,6,
%T 4,5,3,2,3,5,6,7,4,4,4,2,5,3,3,6,4,6,2,5,3,5,3,6,4,6,4,6,3,5,6,6,4,5,
%U 2,4,7,7,3,5,3,3,3,5,4,10,5,4,3,5,3,2,4
%N Number of distinct prime divisors of 44...447 (with n 4s).
%C Also number of distinct prime factors of (10^(n + 1) - 1)*4/9 + 3. - _Stefan Steinerberger_, Feb 21 2006
%H Amiram Eldar, <a href="/A104889/b104889.txt">Table of n, a(n) for n = 1..201</a>
%F a(n) = A001221(A173772(n+1)). - _Amiram Eldar_, Jan 27 2020
%e Number of distinct prime divisors of 47 is 1 (prime).
%e Number of distinct prime divisors of 447 is 2.
%e Number of distinct prime divisors of 4447 is 1 (prime).
%t Table[Length[FactorInteger[(10^(n + 1) - 1)*4/9 + 3]], {n, 1, 40}] (* _Stefan Steinerberger_, Feb 21 2006 *)
%Y Cf. A001221, A104564, A173772.
%K nonn
%O 1,2
%A _Parthasarathy Nambi_, Apr 24 2005
%E More terms from _Stefan Steinerberger_, Feb 21 2006
%E Offset corrected and more terms added by _Amiram Eldar_, Jan 27 2020
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