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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.
2
0, 1, 9, 225, 11025, 1334025, 225450225, 65155115025, 23520996524025, 12442607161209225, 10464232622576958225, 10056127550296456854225, 13766838616355849433434025, 23142055714094182897602596025, 42789661015360144177667200050225, 94522361182930558488466844910947025, 265513312562851938794103367354850193225
OFFSET
0,3
COMMENTS
Terms a(2) .. a(9) are equal to the terms A360435(1..8).
FORMULA
a(n) = A002620(A002110(n)).
For n > 0, a(n) = A061742(n)/4 = A070826(n)^2.
For n > 0, a(n) >= A368704(n) and for n > 1, a(n) >= A360435(n-1).
For n > 0, A000005(a(n)) = A000244(n-1) = 3^(n-1).
MATHEMATICA
Join[{0}, FoldList[Times, 1, Prime[Range[2, 16]]^2]] (* Amiram Eldar, Jan 19 2024 *)
PROG
(PARI)
A002110(n) = prod(i=1, n, prime(i));
A002620(n) = ((n^2)>>2);
CROSSREFS
An upper bound for A368704, and also for A360435(n-1).
Sequence in context: A294971 A001818 A360435 * A095363 A138564 A285985
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 19 2024
STATUS
approved