This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A344946 #34 Jul 23 2021 02:43:49
%S A344946 3,11,709,167449,88362852307,156740126985437,1172447586903041169661
%N A344946 x -> prime(x) iterated prime(n) times, evaluated at n.
%F A344946 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 A344946 a(n) = prime(prime(...(n))) {prime(n) times}.
%e A344946 a(1) = prime(prime(1)) = 3.
%e A344946 a(2) = prime(prime(prime(2))) = 11.
%e A344946 a(3) = prime(prime(prime(prime(prime(3))))) = 709.
%t A344946 nterms=6;Table[Nest[Prime[#]&,n,Prime[n]],{n,nterms}]
%o A344946 (Python)
%o A344946 from sympy import prime
%o A344946 def a(n):
%o A344946 iter = pn = prime(n)
%o A344946 for i in range(1, pn): iter = prime(iter)
%o A344946 return iter
%o A344946 print([a(n) for n in range(1, 6)]) # _Michael S. Branicky_, Jun 03 2021
%o A344946 (PARI) a(n) = my(p = n); for (k=1, prime(n), p=prime(p)); p; \\ _Michel Marcus_, Jun 03 2021
%Y A344946 Cf. A000040, A058009.
%K A344946 nonn,more,hard
%O A344946 1,1
%A A344946 _Paolo Xausa_, Jun 03 2021
%E A344946 a(7) from _Jinyuan Wang_, Jul 12 2021