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%I #9 Sep 15 2023 15:28:43
%S 5,9,10,11,16,17,20,59,96,98,318,387,938,978,1764,8298,10632,11796,
%T 19982
%N Numbers n such that primorial(n)/2 - 1024 is prime.
%C a(20) > 25000. - _Robert Price_, Sep 28 2017
%t k = 1; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k - 1024]&&k>1024, Print[n]; AppendTo[a, n]], {n, 2, 325}]; a
%t Drop[Flatten[Position[FoldList[Times,Prime[Range[400]]],_?(PrimeQ[#/2-1024]&)]],3] (* The program generates the first 12 terms of the sequence. To generate more, increase the Range constant but the program may take a long time to run. *) (* _Harvey P. Dale_, Sep 15 2023 *)
%Y Cf. A067026, A067027, A139439-A139457, A103514.
%K nonn
%O 1,1
%A _Artur Jasinski_, Apr 21 2008
%E Drop 2,3,4 and correct program, a(12)-a(15) from _Ray Chandler_, Jun 16 2013
%E a(16)-a(19) from _Robert Price_, Sep 28 2017
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