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 A225944 Numbers k such that prime(k) divides k^k - 1. 2
 1, 2, 5, 124, 181, 696, 261800, 3834909, 18836480, 51432542, 69709961, 332054520, 3140421767 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(14) > 10^12. - Giovanni Resta, May 11 2020 LINKS Table of n, a(n) for n=1..13. MATHEMATICA Select[Range[10^6], PowerMod[#, #, Prime@#] == 1 &] (* Giovanni Resta, May 23 2013 *) PROG (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, 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 CROSSREFS Cf. A000040, A000312, A048861, A225945. Sequence in context: A294513 A276109 A270481 * A270588 A214648 A175978 Adjacent sequences: A225941 A225942 A225943 * A225945 A225946 A225947 KEYWORD nonn,more AUTHOR Alex Ratushnyak, May 21 2013 EXTENSIONS a(8)-a(13) from Giovanni Resta, May 23 2013 STATUS approved

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Last modified April 22 12:55 EDT 2024. Contains 371900 sequences. (Running on oeis4.)