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%I #2 Mar 30 2012 19:00:23
%S 4,9,12,15,16,18,21,24,25,26,28,32,33,34,36,38,39,40,42,45,48,49,50,
%T 51,52,55,56,57,60,63,64,65,68,69,70,72,74,76,77,78,80,81,84,86,87,88,
%U 90,91,93,94,95,98,100
%N Composites (A002808) with nonprime (A018252) subscripts.
%C a(n) = composite(nonprime(n)) = A002808(A018252(n)). a(n) U A065858(n) = A002808(n), a(n+1) U A022449(n) = A002808(n) for n >= 1. a(1) = 4, a(n) = A050435(n-1) = composites (A002808) with composite (A002808) subscripts for n >=2.
%e a(5) = 16 because a(5) = c(b(5)) = c(9) = 16, c = composite, b = nonprime.
%K nonn
%O 1,1
%A _Jaroslav Krizek_, Mar 13 2010
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