cp's OEIS Frontend

A088730 Numbers of the form p^p - 1, where p is a prime.

%I A088730 #28 Sep 08 2022 08:45:12
%S A088730 3,26,3124,823542,285311670610,302875106592252,827240261886336764176,
%T A088730 1978419655660313589123978,20880467999847912034355032910566,
%U A088730 2567686153161211134561828214731016126483468
%N A088730 Numbers of the form p^p - 1, where p is a prime.
%C A088730 Sum of reciprocals = 0.3721161884983118696170302604..
%H A088730 Vincenzo Librandi, <a href="/A088730/b088730.txt">Table of n, a(n) for n = 1..77</a>
%F A088730 a(n) = A051674(n) - 1. - _R. J. Mathar_, Jul 15 2007
%e A088730 a(1) = 3 because the first prime is 2 and 2^2 - 1 = 3.
%e A088730 a(2) = 26 because the second prime is 3 and 3^3 - 1 = 26.
%e A088730 a(3) = 3124 because the fifth prime is 5 and 5^5 - 1 = 3124.
%t A088730 Table[Prime[n]^Prime[n] - 1, {n, 10}] (* _Alonso del Arte_, May 22 2013 *)
%t A088730 #^#-1&/@Prime[Range[10]] (* _Harvey P. Dale_, Jun 10 2013 *)
%o A088730 (PARI) a(n)={my(p=prime(n)); p^p-1;} \\ _Joerg Arndt_, May 27 2013
%o A088730 (Magma) [p^p-1: p in PrimesUpTo(20)]; // _Vincenzo Librandi_, Mar 27 2014
%Y A088730 Cf. A051674, A088807, A125135 (factorizations).
%K A088730 nonn
%O A088730 1,1
%A A088730 _Cino Hilliard_, Nov 23 2003
%E A088730 More terms from _Ray Chandler_, Feb 21 2004