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%I #9 Apr 19 2023 07:49:03
%S 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,17,18,19,21,22,23,25,27,29,31,33,
%T 34,37,41,43,44,49,51,59,61,66,67,85,99,101,109,163
%N Numbers which are not the sum of two 3-almost primes.
%C 3-almost prime analog of A072966, numbers which are not the sum of two semiprimes. In general, it seems that almost all even numbers can be written as the sum of two k-almost primes for any positive integer k. - _T. D. Noe_, Nov 06 2006
%F Complement of Sumset {A014612} + {A014612}.
%t nn=10000; t3=Select[Range[2,nn], Plus@@Last/@FactorInteger[ # ]==3&]; t3sum=Table[0,{nn}]; Do[n=t3[[i]]+t3[[j]]; If[n<=nn, t3sum[[n]]=1], {i,Length[t3]}, {j,i,Length[t3]}]; Flatten[Position[t3sum,0]] (* _T. D. Noe_, Nov 06 2006 *)
%Y Cf. A014612, A072966.
%K easy,fini,full,nonn
%O 1,2
%A _Jonathan Vos Post_, Sep 27 2006
%E Edited by _T. D. Noe_, Nov 06 2006