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%I #7 Mar 30 2012 18:50:35
%S 0,0,1,2,3,3,3,4,5,5,5,7,6,6,8,6,8,10,6,8,10,8,10,11,10,9,12,10,10,15,
%T 10,12,14,10,14,15,14,14,16,13,13,18,12,14,20,14,15,18,14,18,20,16,17,
%U 19,18,19,23,18,17,26,15,18,25,16,21,23,19,19,22,22,22,26,21
%N Number of distinct prime-factors of {2*n-p: 2<p<2*n, p prime}.
%H <a href="/index/Go#Goldbach">Index entries for sequences related to Goldbach conjecture</a>
%e n=10, 2*10=20: 20-3=17, 20-5=15=3*5, 20-7=13, 20-11=9=3*3, 20-13=7, 20-17=3 and 20-19=1: with a(10)=5 distinct primes 3,5,7,13,17.
%Y Cf. A084766.
%K nonn
%O 1,4
%A _Reinhard Zumkeller_, Jun 03 2003
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