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%I A158340
%S A158340 4,8,9,25,27,30,32,36,42,49,64,66,70,72,78,100,102,105,108,110,
%T A158340 114,121,125,130,148,154,165,170,174,180,182,186,190,195,196,200,222,225,
               230,231,238,243,246,252,255,256,258,266,273,282,285,286,290,300,310,
               318,322
%N A158340 Composite numbers k such that number of prime factors of k + number of 
               divisors of k = prime.
%e A158340 If composite=2*2=4(1, 2, 4) and 2+3=5=prime, then 4=a(1). If composite=2*2*2=8(1, 
               2, 4, 8) and 3+4=7=prime, then 8=a(2). If composite=9=3*3=9(1, 3, 
               9) and 2+3=5=prime, then 9=a(3), etc.
%Y A158340 Cf. A000040, A002808, A035004.
%Y A158340 Adjacent sequences: A158337 A158338 A158339 this_sequence A158341 A158342 
               A158343
%K A158340 nonn
%O A158340 1,1
%A A158340 Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Mar 16 2009, Nov 14 2009

    
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Last modified December 16 17:18 EST 2009. Contains 170825 sequences.


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