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A066205 a(n) = Product_{k=1..n} prime(2k-1), where prime(k) is k-th prime.

%I A066205 #30 Jan 13 2022 10:01:14
%S A066205 2,10,110,1870,43010,1333310,54665710,2569288370,151588013830,
%T A066205 10156396926610,741416975642530,61537608978329990,5969148070898009030,
%U A066205 614822251302494930090,67015625391971947379810,8510984424780437317235870,1166004866194919912461314190
%N A066205 a(n) = Product_{k=1..n} prime(2k-1), where prime(k) is k-th prime.
%C A066205 Equivalently, a(n) is the product of the first n odd-indexed primes. - _Jon E. Schoenfield_, Jan 12 2022
%H A066205 Harry J. Smith, <a href="/A066205/b066205.txt">Table of n, a(n) for n = 1..100</a>
%e A066205 a(3) = prime(1) * prime(3) * prime(5) = 2 * 5 * 11 = 110.
%p A066205 a:= proc(n) option remember;
%p A066205      `if`(n=0, 1, a(n-1)*ithprime(2*n-1))
%p A066205     end:
%p A066205 seq(a(n), n=1..17);  # _Alois P. Heinz_, Jan 12 2022
%t A066205 FoldList[Times, Array[Prime[2 # - 1] &, 17]] (* _Michael De Vlieger_, Jan 12 2022 *)
%o A066205 (PARI) { for (n=1, 100, p=1; for (k=1, n, p*=prime(2*k - 1)); write("b066205.txt", n, " ", p) ) } \\ _Harry J. Smith_, Feb 05 2010
%o A066205 (PARI) a(n) = prod(k=1, n, prime(2*k-1)); \\ _Michel Marcus_, Jan 13 2022
%Y A066205 Cf. A000040, A002110, A066206.
%K A066205 nonn
%O A066205 1,1
%A A066205 _Leroy Quet_, Dec 16 2001