A136176 - OEIS

%I #13 Mar 20 2018 19:02:00

%S 0,1,1,1,1,2,1,0,0,2,1,2,1,2,2,1,1,2,1,2,2,2,1,2,0,2,1,2,1,3,1,0,2,2,

%T 2,2,1,2,2,1,1,3,1,2,1,2,1,2,0,2,2,2,1,2,2,1,2,2,1,3,1,2,1,0,2,3,1,2,

%U 2,3,1,2,1,2,1,2,2,3,1,2,0,2,1,3,2,2,2,1,1,3,2,2,2,2,2,1,1,2,1,2,1,3,1,1,3

%N Number of exponents in the prime factorization of n which divide n.

%H Antti Karttunen, <a href="/A136176/b136176.txt">Table of n, a(n) for n = 1..65537</a>

%e 128000 = 2^10 * 5^3. 10 divides 128000, but 3 does not. So a(128000) = 1.

%t Table[Length[Select[Table[FactorInteger[n][[i, 2]], {i, 1, Length[FactorInteger[n]]}], Mod[n, # ] == 0 &]], {n, 1, 90}] (* _Stefan Steinerberger_, Dec 21 2007 *)

%o (PARI) A136176(n)=sum(j=1,#t=factor(n)[,2]~,!(n%t[j])) \\ _M. F. Hasler_, Dec 21 2007

%Y Cf. A136177.

%K nonn,easy

%O 1,6

%A _Leroy Quet_, Dec 19 2007

%E More terms from _M. F. Hasler_ and _Stefan Steinerberger_, Dec 21 2007