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Numbers which are not the sum of two squarefree semiprimes.
0

%I #10 Dec 04 2019 09:25:12

%S 0,1,2,3,4,5,6,7,8,9,10,11,13,14,15,17,18,19,22,23,26,33,34,38,46,51,

%T 58,62,82

%N Numbers which are not the sum of two squarefree semiprimes.

%C Is this a finite sequence?

%C Most probably yes. Since almost all semiprimes are squarefree, this is essentially the same as A072966. The graph of A072931 would not change qualitatively if only squarefree semiprimes were considered. - _M. F. Hasler_, Dec 03 2019

%e a(10) = 11 since there is no way to represent 11 as a sum of two squarefree semiprimes. 12 is not a term since 12 = 6 + 6.

%Y Cf. A006881, A072966.

%K nonn

%O 1,3

%A _Lior Manor_, Nov 14 2019