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A084743 Smallest prime of the form n^k + k, or 0 if no such prime exists. 0

%I

%S 2,3,11,5

%N Smallest prime of the form n^k + k, or 0 if no such prime exists.

%C a(5) > 5^18 +18 = 3814697265643. Conjecture: No entry is zero.

%C See A093324 for the values of k. The next term, a(5) = 5^7954+7954, has 5560 digits and is too large to display here. - _T. D. Noe_, Oct 05 2007

%C a(6)-a(10) are 7, 54116956037952111668959660883, 16296287810675888690147565507275025288411747149327490005089123594835050398106693649467179109, 83, and 11, respectively. a(11) > 11^190000 + 190000. See A093324 for the k-values. - _Derek Orr_, Aug 08 2014

%o (PARI)

%o a(n)=for(k=1,8000,s=n^k+k;if(ispseudoprime(s),return(s)))

%o vector(10,n,a(n)) \\ _Derek Orr_, Aug 08 2014

%Y Cf. A093324.

%K nonn

%O 1,1

%A _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 15 2003

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Last modified May 26 04:26 EDT 2022. Contains 354074 sequences. (Running on oeis4.)