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Number of partitions of the n-th semiprime into two semiprimes.
3

%I #3 Mar 30 2012 18:51:05

%S 0,0,0,1,1,1,1,0,2,1,0,1,3,1,3,1,3,1,5,2,2,1,3,3,3,4,2,2,4,4,8,3,3,8,

%T 4,5,8,3,6,7,3,5,7,9,5,5,7,10,7,6,11,5,8,7,5,9,8,8,9,6,10,8,8,7,11,9,

%U 9,10,9,7,15,12,10,11,9,10,15,9,12,10,12,12,13,11,11,11,15,12,17,12,13,16,14

%N Number of partitions of the n-th semiprime into two semiprimes.

%C a(n) = A072931(A001358(n)).

%H R. Zumkeller, <a href="/A171963/b171963.txt">Table of n, a(n) for n = 1..1000</a>

%e a(13) = A072931(A001358(13)) = A072931(35) = #{26+9,25+10,21+14} = #{2*13+3*3,5*5+2*5,3*7+2*7} = 3.

%K nonn

%O 1,9

%A _Reinhard Zumkeller_, Jan 21 2010