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 A218863 Smallest prime p such that n*p is greater than the greatest prime factors of p^n - 1 and of p^n + 1. 2
 3, 3, 37, 2383, 69011, 4027 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(7) > 4000000. - T. D. Noe, Nov 08 2012 LINKS EXAMPLE 4027^6 - 1 = 2^3*3^2*7*11*13*19*53*61*229*709*1759*3373, 4027^6 + 1 = 2*5*37*41*1069*1381*1993*9733*9817, and 6*4027 > 3373 and 6*4027 > 9817, 3^1 - 1 = 2, 3^1 + 1 = 2^2 and 3 > 2. MAPLE A218863 := proc(n)     p := 2 ;     for i from 1 do         max(op(numtheory[factorset](p^n-1))) ;         if n*p > % then             max(op(numtheory[factorset](p^n+1))) ;             if n*p > % then                 return p;             end if;         end  if;         p := nextprime(p) ;     end do: end proc: # R. J. Mathar, Nov 07 2012 MATHEMATICA Table[p = 2; While[n*p <= FactorInteger[p^n - 1][[-1, 1]] || n*p <= FactorInteger[p^n + 1][[-1, 1]], p = NextPrime[p]]; p, {n, 6}] (* T. D. Noe, Nov 07 2012 *) CROSSREFS Sequence in context: A303820 A206477 A219210 * A082394 A308645 A086889 Adjacent sequences:  A218860 A218861 A218862 * A218864 A218865 A218866 KEYWORD nonn AUTHOR Robin Garcia, Nov 07 2012 STATUS approved

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Last modified September 21 11:18 EDT 2019. Contains 327253 sequences. (Running on oeis4.)