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 A086693 #25 Sep 08 2022 08:45:11
%S A086693 2,9,445,65685,11262113374,9373678643933,17547676024364306476,
%T A086693 36020106660104388871845
%N A086693 Number of primes less than prime(n)^prime(n).
%F A086693 a(n) = A064151(prime(n)) = A000720(A051674(n)). - _Michel Marcus_, Mar 17 2015
%e A086693 There are 9 primes less than 3^3 = 27, namely 2,3,5,7,11,13,17,19,23. Since 3 is prime(2), a(2) = 9.
%t A086693 f[n_] := Block[{p = Prime@ n}, PrimePi[p^p]]; Array[f, 5] (* _Michael De Vlieger_, Mar 17 2015 *)
%o A086693 (PARI) primeslesspp(n) = /* primes less than p^p */ { forprime(x=2, n, y=primepi(x^x); print1(y", "); ); }
%o A086693 (Magma) [ #PrimesUpTo(NthPrime(n)^NthPrime(n)): n in [1..4] ]; // _Vincenzo Librandi_, Mar 17 2015
%Y A086693 Cf. A064151.
%K A086693 hard,more,nonn
%O A086693 1,1
%A A086693 _Cino Hilliard_, Jul 28 2003
%E A086693 a(5)-a(7) from _David Baugh_, Mar 17 2015
%E A086693 a(8) from _Chai Wah Wu_, Apr 18 2018