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A275588
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a(1) = 1; thereafter a(n) = (Sum_{k=1..n-1} a(k)) ^ Product_{k=1..n-1} a(k).
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1
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OFFSET
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1,3
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COMMENTS
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a(6) is roughly 10^(5.72199*10^44).
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LINKS
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EXAMPLE
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a(4) = (a(1) + a(2) + a(3)) ^ (a(1)*a(2)*a(3)) = (1 + 1 + 2)^(1*1*2) = 4^2 = 16.
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MATHEMATICA
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a[1] = 1; a[n_] := a[n] = Sum[a[k], {k, n - 1}]^Product[a[k], {k, n - 1}]; Table[a[n], {n, 0, 5}] (* Michael De Vlieger, Aug 04 2016 *)
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PROG
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(PARI) a(n) = if(n==1, 1, if(n>1, sum(k=1, n - 1, a(k)) ^ prod(k=1, n - 1, a(k))))
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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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