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A321340
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a(1) = 1; thereafter a(n) = a(n-1) * prime(n-1)^a(n-1).
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1
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OFFSET
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1,2
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COMMENTS
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The prime factorization of a(n) describes all previous terms in the sequence: a(n) = prime(1)^a(1) * prime(2)^a(2) * prime(3)^a(3) * ...* prime(n-1)^a(n-1).
An infinite and monotonically increasing sequence which grows very rapidly.
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LINKS
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EXAMPLE
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68664550781250 = 2 * 3^2 * 5^18 = prime(1)^1 * prime(2)^2 * prime(3)^18.
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MATHEMATICA
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Nest[Append[#, #[[-1]] Prime[Length@ #]^#[[-1]] ] &, {1}, 3] (* Michael De Vlieger, Nov 05 2018 *)
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PROG
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(PARI) apply( ppp(n) = prod(i=1, n-1, prime(i)^ppp(i)), [1..4] )
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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