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%I #6 May 18 2020 19:57:24
%S 1,2,1,3,1,6,1,4,1,4,1,11,1,4,1,5,1,10,1,9,1,3,1,19,1,4,1,7,1,26,1,5,
%T 1,2,1,25,1,2,1,14,1,25,1,6,1,3,1,30,1,6,1,6,1,16,1,12,1,3,1,81,1,2,1,
%U 6,1,18,1,5,1,18,1,41,1,4,1,3,1,22,1,20,1,3,1,71,1,3,1,11,1,76,1,5,1,3,1,38
%N Duplicate of A084419.
%e The divisors of 4 are D = {1, 2, 4} and the subsets of D are {{}, {1}, {2}, {4}, {1, 2}, {1, 4}, {2, 4}, {1, 2, 4}}. Taking the product of elements in these subsets and adding 1 yields {1, 2, 3, 5, 3, 5, 9, 9}, of which the primes are {2, 3, 5}.
%t Do[l = Subsets[Divisors[n]]; l = Union[Map[Times @@ # + 1&, l]]; Print[Length[Select[l, PrimeQ]]], {n, 100}]
%K dead
%O 1,2
%A _Ryan Propper_, Jun 04 2006
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