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%I #34 Jul 23 2021 02:43:49
%S 3,11,709,167449,88362852307,156740126985437,1172447586903041169661
%N x -> prime(x) iterated prime(n) times, evaluated at n.
%F a(n) = prime^{prime(n)}(n), with prime^{0}(n) = n and prime^{k}(n) = prime(prime^{k-1}(n)) for 1 <= k <= prime(n).
%F a(n) = prime(prime(...(n))) {prime(n) times}.
%e a(1) = prime(prime(1)) = 3.
%e a(2) = prime(prime(prime(2))) = 11.
%e a(3) = prime(prime(prime(prime(prime(3))))) = 709.
%t nterms=6;Table[Nest[Prime[#]&,n,Prime[n]],{n,nterms}]
%o (Python)
%o from sympy import prime
%o def a(n):
%o iter = pn = prime(n)
%o for i in range(1, pn): iter = prime(iter)
%o return iter
%o print([a(n) for n in range(1, 6)]) # _Michael S. Branicky_, Jun 03 2021
%o (PARI) a(n) = my(p = n); for (k=1, prime(n), p=prime(p)); p; \\ _Michel Marcus_, Jun 03 2021
%Y Cf. A000040, A058009.
%K nonn,more,hard
%O 1,1
%A _Paolo Xausa_, Jun 03 2021
%E a(7) from _Jinyuan Wang_, Jul 12 2021
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