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%I A109422
%S A109422 4,8,9,16,25,27,30,32,36,42,49,64,66,70,72,78,81,100,102,105,108,110,
%T A109422 114,120,121,125,128,130,138,144,154,165,168,169,170,174,180,182,186,
%U A109422 190,195,196,200,216,222,225,230,231,238,240,243,246,252,255,256,258
%N A109422 Numbers n such that tau(n)/bigomega(n) is not an integer [tau(n) =number 
               of divisors of n; bigomega(n)=number of prime divisors of n, counted 
               with multiplicities].
%C A109422 Integers greater than 1 and not in A109421.
%e A109422 16 is in the sequence because tau(16)=5 (1,2,4,8,16) and bigomega(16)=4 
               (2,2,2,2) and so tau(16)/bigomega(16)=5/4.
%e A109422 12 is not in the sequence because tau(12)=6 (1,2,3,4,6,12) and bigomega(12)=3 
               (2,2,3) and so tau(12)/bigomega(12)=2
%p A109422 with(numtheory): b:=proc(n) if type(tau(n)/bigomega(n),integer)=false 
               then n else fi end: seq(b(n),n=2..300);
%Y A109422 Complement of A109421.
%Y A109422 Sequence in context: A100657 A140104 A127398 this_sequence A158804 A080366 
               A001694
%Y A109422 Adjacent sequences: A109419 A109420 A109421 this_sequence A109423 A109424 
               A109425
%K A109422 nonn
%O A109422 1,1
%A A109422 Emeric Deutsch (deutsch(AT)duke.poly.edu), Jun 28 2005

    
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Last modified December 1 13:27 EST 2009. Contains 167806 sequences.


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