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A369059 a(0) = 0, and for n > 0, a(n) is the square of the product of first n-1 odd primes.

%I A369059 #15 Jan 19 2024 16:55:51
%S A369059 0,1,9,225,11025,1334025,225450225,65155115025,23520996524025,
%T A369059 12442607161209225,10464232622576958225,10056127550296456854225,
%U A369059 13766838616355849433434025,23142055714094182897602596025,42789661015360144177667200050225,94522361182930558488466844910947025,265513312562851938794103367354850193225
%N A369059 a(0) = 0, and for n > 0, a(n) is the square of the product of first n-1 odd primes.
%C A369059 Terms a(2) .. a(9) are equal to the terms A360435(1..8).
%H A369059 <a href="/index/Pri#primorial_numbers">Index entries for sequences related to primorial numbers</a>
%F A369059 a(n) = A002620(A002110(n)).
%F A369059 For n > 0, a(n) = A061742(n)/4 = A070826(n)^2.
%F A369059 For n > 0, a(n) >= A368704(n) and for n > 1, a(n) >= A360435(n-1).
%F A369059 For n > 0, A000005(a(n)) = A000244(n-1) = 3^(n-1).
%t A369059 Join[{0}, FoldList[Times, 1, Prime[Range[2, 16]]^2]] (* _Amiram Eldar_, Jan 19 2024 *)
%o A369059 (PARI)
%o A369059 A002110(n) = prod(i=1,n,prime(i));
%o A369059 A002620(n) = ((n^2)>>2);
%o A369059 A369059(n) = A002620(A002110(n));
%Y A369059 Cf. A000005, A000244, A002110, A002620, A061742, A070826, A360435.
%Y A369059 An upper bound for A368704, and also for A360435(n-1).
%K A369059 nonn
%O A369059 0,3
%A A369059 _Antti Karttunen_, Jan 19 2024