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 A065895 #20 Aug 10 2024 03:54:55
%S A065895 0,1,17,201,2679,41834,757857,15699344,366719682,9544947488,
%T A065895 274049557236,8606313278052,293501427948319,10802628699872589,
%U A065895 426834313802135110,18021087789674333872,809692585861972457700,38575004548436059251080,1942399549000209200252133
%N A065895 Which composite number is n^n ?: a(n) = k such that A002808(k) = n^n, or 0 if n^n is not composite.
%F A065895 a(n) = n^n - A064151(n) - 1. - _Amiram Eldar_, Aug 09 2024
%e A065895 For n = 3: 3^3 = 27 = A002808(17) is the 17th composite number.
%t A065895 Table[n^n - PrimePi[n^n] - 1, {n, 1, 12}]
%o A065895 (PARI) a(n) = my(m = n^n); m - primepi(m) - 1; \\ _Amiram Eldar_, Aug 09 2024
%Y A065895 Cf. A000312, A000720, A002808, A064151.
%K A065895 nonn
%O A065895 1,3
%A A065895 _Labos Elemer_, Nov 28 2001
%E A065895 More terms from _Robert G. Wilson v_ and _Vladeta Jovovic_, Nov 29 2001
%E A065895 Name clarified and a(13)-a(19) calculated from the data at A064151 and added by _Amiram Eldar_, Aug 09 2024