A225944 Numbers k such that prime(k) divides k^k - 1.
1, 2, 5, 124, 181, 696, 261800, 3834909, 18836480, 51432542, 69709961, 332054520, 3140421767
Offset: 1
Programs
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Mathematica
Select[Range[10^6], PowerMod[#, #, Prime@#] == 1 &] (* Giovanni Resta, May 23 2013 *)
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Python
primes = [] n = 0 def addPrime(k): global n for p in primes: if k%p==0: return if p*p > k: break primes.append(k) n += 1 if (n**n-1) % k == 0: print(n, end=", ") addPrime(2) addPrime(3) for i in range(5, 10000000, 6): addPrime(i) addPrime(i+2) -
Python
from sympy import nextprime, prime from itertools import count, islice def agen(startn=1): # generator of terms pn = prime(startn) for n in count(startn): if pow(n, n, pn) == 1: yield n pn = nextprime(pn) print(list(islice(agen(), 7))) # Michael S. Branicky, May 25 2023
Extensions
a(8)-a(13) from Giovanni Resta, May 23 2013
Comments