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%I #12 Aug 24 2021 01:45:06
%S 1,4,10,16,22,28,40,52,58,70,88,100,112,130,136,148,196,232,238,250,
%T 256,280,310,316,352,382,400,418,430,442,478,490,556,562,592,598,616,
%U 640,682,742,772,796,808,820,862,880,928,970,976,1030,1048,1060,1096,1102
%N Numbers k such that k+1 is the smallest prime factor of k^3 + 3^k.
%C Except for the first term, 2k+1 is composite.
%o (PARI) isok(n) = factor(n^3+3^n)[1, 1] == (n+1); \\ _Michel Marcus_, Oct 06 2013
%Y Cf. A001585.
%K nonn
%O 1,2
%A _Zak Seidov_ and _Max Alekseyev_, Jun 25 2005