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Product_{k=1..n} k^(k^3).
14

%I #13 Sep 08 2015 13:54:51

%S 1,256,1952152956156672,

%T 664283228512699358734362008580999708796213453161234432

%N Product_{k=1..n} k^(k^3).

%C The next term a(5) has 142 digits.

%H Vaclav Kotesovec, <a href="/A255321/b255321.txt">Table of n, a(n) for n = 1..7</a>

%F a(n) ~ A243263 * n^(n^2*(n+1)^2/4 - 1/120) / exp(n^4/16 - n^2/12).

%t Table[Product[k^(k^3), {k, 1, n}], {n, 1, 6}]

%o (PARI) a(n)=prod(k=2,n,k^k^3) \\ _Charles R Greathouse IV_, Sep 08 2015

%Y Cf. A002109, A051675, A255323, A255344, A243263.

%K nonn

%O 1,2

%A _Vaclav Kotesovec_, Feb 21 2015