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%I #13 May 25 2023 11:01:29
%S 1,6,60,136,124796,3919272,18363918,153037808,965108649,3140421892,
%T 5961162423,20437804784
%N Numbers k such that prime(k) divides k^k + 1.
%C a(12) > 2*10^10. - _Giovanni Resta_, May 23 2013
%t Select[Range[10^6], (p = Prime[#]; PowerMod[#, #, p] == p - 1) &] (* _Giovanni Resta_, May 23 2013 *)
%o (Python)
%o from sympy import nextprime, prime
%o from itertools import count, islice
%o def agen(startn=1): # generator of terms
%o pn = prime(startn)
%o for n in count(startn):
%o if pow(n, n, pn) == pn - 1:
%o yield n
%o pn = nextprime(pn)
%o print(list(islice(agen(), 5))) # _Michael S. Branicky_, May 25 2023
%Y Cf. A000040, A000312, A014566, A225944.
%K nonn,more
%O 1,2
%A _Alex Ratushnyak_, May 21 2013
%E a(6)-a(11) from _Giovanni Resta_, May 23 2013
%E a(12) from _Michael S. Branicky_, May 25 2023