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Semiprimes of the form 2^k + k.
4

%I #20 Oct 26 2024 10:45:45

%S 6,2059,8388631,17179869218,576460752303423547,590295810358705651781,

%T 154742504910672534362390615,39614081257132168796771975263,

%U 664613997892457936451903530140172407,10633823966279326983230456482242756731,680564733841876926926749214863536423041

%N Semiprimes of the form 2^k + k.

%H Amiram Eldar, <a href="/A089535/b089535.txt">Table of n, a(n) for n = 1..26</a>

%F a(n) = 2^A085745(n) + A085745(n).

%t Select[Table[2^k+k,{k,200}],PrimeOmega[#]==2&] (* _Harvey P. Dale_, Aug 11 2024 *)

%Y Intersection of A001358 and A006127.

%Y Cf. A085745, A089536, A089537, 129962.

%K nonn

%O 1,1

%A _Ray Chandler_, Nov 08 2003

%E a(10)-a(11) from _Jinyuan Wang_, Jul 30 2021