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%I #19 Oct 20 2021 09:06:13
%S 35,51,57,65,77,87,93,95,119,121,123,143,145,155,161,177,185,187,203,
%T 205,209,215,217,219,221,237,247,249,267,287,289,291,299,301,303,305,
%U 321,323,327,329,335,341,365,371,377,393,395,407,413,415,417,427,437
%N Odd semiprimes m such that m-2 is composite.
%C A087942(a(n)) = 0.
%C Assuming Goldbach's conjecture that every even number greater than 2 is the sum of two primes, these are the numbers that are the product of two primes but not the sum of two primes. - _Michael B. Porter_, Feb 08 2013
%H Bill McEachen, <a href="/A089268/b089268.txt">Table of n, a(n) for n = 1..10000</a>
%t Take[Select[Union[Flatten[Table[Prime[i] Prime[j], {i, 2, 25}, {j, 2, 25}]]], Not[PrimeQ[# - 2]] &], 50] (* _Alonso del Arte_, Feb 08 2013 *)
%o (PARI) isok(m) = (m%2) && (bigomega(m)==2) && !isprime(m-2); \\ _Michel Marcus_, Oct 19 2021
%Y Cf. A062721, A046315, A001358.
%K nonn
%O 1,1
%A _Reinhard Zumkeller_, Oct 28 2003
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