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 A034915 Primes of the form p^k - p + 1 for prime p. 2
 3, 7, 31, 43, 79, 127, 157, 241, 337, 727, 1321, 3121, 4423, 6163, 6841, 8191, 19183, 19681, 22651, 26407, 28549, 29761, 37057, 68881, 78121, 113233, 117643, 121453, 130303, 131071, 143263, 208393, 292141, 371281, 375157, 412807, 524287, 527803 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Related to hyperperfect numbers of a certain form. Since x^k-x+1 is divisible by x^2-x+1 for k==2 (mod 6), none of k=8,14,20,... occur. - Robert Israel, Mar 20 2018 LINKS Robert Israel, Table of n, a(n) for n = 1..4960 J. S. McCranie, A study of hyperperfect numbers, J. Int. Seqs. Vol. 3 (2000) #P00.1.3. EXAMPLE 11^3 - 11 + 1 = 1321 is prime, so 1321 is a term. MAPLE N:= 10^6: # to get all terms <= N Res:= NULL; p:= 1: do p:= nextprime(p); if p^2-p+1>N then break fi; for i from 2 to floor(log[p](N+p-1)) do if isprime(p^i-p+1) then Res:= Res, p^i-p+1 fi od od: sort(convert({Res}, list)); # Robert Israel, Mar 20 2018 CROSSREFS Contains A074268. Sequence in context: A110581 A128436 A213899 * A145479 A077315 A365423 Adjacent sequences: A034912 A034913 A034914 * A034916 A034917 A034918 KEYWORD nonn AUTHOR Jud McCranie STATUS approved

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Last modified April 19 19:02 EDT 2024. Contains 371798 sequences. (Running on oeis4.)