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%I #14 Jul 24 2023 10:57:53
%S 1,3,5,7,8,9,11,12,14,17,20,24,30,34,44,72,85,86,92,115,122,125,132,
%T 142,150,161,162,181,186,198,224,248,252,282,283,290,307,319,321,344,
%U 350,376,445,476,567,623,676,682,704,741,749,786,803,806,893,1014,1046,1079
%N a(n) is the smallest positive integer such that b * (Product_{k=1..n} a(k)) + 1 is prime, with b = 4.
%C Is this A144717 without the 2? - _R. J. Mathar_, Jul 24 2023
%e 4*1+1=5 is prime => a(1)=1.
%e 4*1*2+1=9 is not prime (omitted).
%e 4*1*3+1=13 is prime => a(2)=3.
%t k = 4; a = {}; Do[If[PrimeQ[k n + 1], k = k n; AppendTo[a, n]], {n, 1, 3000}]; a (* Artur Jasinski *)
%Y Cf. A046966, A046972, A144717, A144718, A144722, A144723, A144725, A144726, A144727, A144728, A144729, A144730, A144731.
%K nonn
%O 1,2
%A _Artur Jasinski_, Sep 19 2008
%E Definition corrected by _Georg Fischer_, Jun 18 2021
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