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%I #6 Jun 16 2018 18:31:26
%S 1,2,2,4,2,8,2,12,4,8,2,48,2,20,8,24,2,32,2,120,20,8,2,288,4,28,8,120,
%T 2,320,2,120,8,20,20,576,2,20,28,480,2,320,2,264,32,8,2,4320,10,200,
%U 20,168,2,320,8,1200,20,8,2,11520,2,44,80,600,28,704,2,300,8,800,2,6912,2,44,80,300,20,448,2,31200,40,8,2,72000,20,20,8
%N a(n) = Product_{d|n, d<n} prime(A305793(1+d)-1), where A305973(k) records the prime signature of 2k-1.
%H Antti Karttunen, <a href="/A305982/b305982.txt">Table of n, a(n) for n = 1..8192</a>
%F a(n) = Product_{d|n, d<n} A008578(A305793(1+d)).
%o (PARI) A305982(n) = { my(m=1); fordiv(n, d, if((d<n), m *= prime(A305973(1+d)-1))); (m); }; \\ Needs also code from A305973.
%Y Cf. A305973, A305983 (rgs-transform), A305984.
%K nonn
%O 1,2
%A _Antti Karttunen_, Jun 15 2018