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Semiprimes p*q such that 2*p divides q-1.
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%I #12 Nov 24 2023 08:58:56

%S 10,21,26,34,39,55,57,58,74,82,93,106,111,122,129,146,155,178,183,194,

%T 201,202,203,205,218,219,226,237,253,274,291,298,301,305,309,314,327,

%U 346,355,362,381,386,394,417,453,458,466,471,482,489,497,505,514,538

%N Semiprimes p*q such that 2*p divides q-1.

%C These terms and their squarefree proper multiples are the squarefree numbers that never appear as terms in A367566.

%e 10 is a term: 10 = 2*5, and 2*2 | 5 - 1.

%e 33 is not a term: 33 = 3*11, but 2*3 does not divide 11 - 1.

%Y Cf. A156592, A231966, A367566.

%Y Subsequence of A006881.

%K nonn

%O 1,1

%A _Jon E. Schoenfield_, Nov 24 2023