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a(n) = Product_{d|n, d>1} prime(A305788(d)-1).
3

%I #8 Jun 12 2018 10:16:10

%S 1,2,2,6,3,20,2,42,10,66,2,660,2,20,42,546,13,1700,2,3762,12,20,5,

%T 106260,6,20,110,660,5,106260,2,15834,20,806,30,2075700,2,20,44,

%U 1079694,2,6600,5,660,4830,170,2,42822780,10,660,754,660,5,691900,12,106260,44,170,2,2731625820,2,20,660,680862,114,17000,2,113646,30,56100,5

%N a(n) = Product_{d|n, d>1} prime(A305788(d)-1).

%H Antti Karttunen, <a href="/A305814/b305814.txt">Table of n, a(n) for n = 1..8192</a>

%H <a href="/index/Ge#GF2X">Index entries for sequences operating on GF(2)[X]-polynomials</a>

%F a(n) = Product_{d|n} A008578(A305788(d)).

%o (PARI) A305814(n) = { my(m=1); fordiv(n, d, if(d>1, m *= prime(A305788(d)-1))); (m); }; \\ Needs also code from A305788.

%Y Cf. A008578, A278233, A305788, A305812, A305815 (rgs-transform).

%K nonn

%O 1,2

%A _Antti Karttunen_, Jun 11 2018