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Numbers k such that the k-th semiprime == 10 (mod k).
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%I #20 Oct 13 2022 12:48:55

%S 1,2,4,12,14,64,79,81,83,84,85,6879,6901,613419,613445,613571,613605,

%T 58155568,6384425499,6384425501,6384425551,6384425553,6384425635,

%U 819217006167,819217006202,819217006763,819217006854,819217006872

%N Numbers k such that the k-th semiprime == 10 (mod k).

%C a(29) > 10^12. - _Lucas A. Brown_, Oct 18 2020

%H Lucas A. Brown, <a href="https://github.com/lucasaugustus/oeis/blob/main/semiprimemods.py">semiprimemods.py</a>

%e a(3)=12 is a term because the 12th semiprime (i.e., 34) == 10 (mod 12).

%Y Cf. A001358.

%K nonn,hard,more

%O 1,2

%A _Shyam Sunder Gupta_, May 07 2005

%E a(18) from _Donovan Johnson_, Oct 29 2008

%E a(19)-a(28) by _Lucas A. Brown_, Oct 18 2020

%E a(1)-a(3) by _Lucas A. Brown_, Nov 23 2020