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Least positive k such that n^n + k is a Chen prime.
0

%I #7 Dec 15 2017 17:36:56

%S 1,1,2,1,12,23,4,73,100,19,450,281,114,241,56,51,582,527,412,771,230,

%T 997,440,95,1882,1117,224,1213,1968,29,168,421,104,2383,876,1085,5776,

%U 253,742,4909,402,2045,3414,403,2366,705,2124,6455,5662,2329,1568,20101

%N Least positive k such that n^n + k is a Chen prime.

%t (* After loading the NumberTheory package *) SemiPrimeQ[n_] := (f = FactorIntegerECM[n]; PrimeQ[f] && PrimeQ[n/f]); ShenPrimeQ[n_] := (PrimeQ[n] && (PrimeQ[n + 2] || SemiPrimeQ[n + 2])); Do[k = 1; While[ !ShenPrimeQ[n^n + k], k++ ]; Print[k], {n, 100}] (* _Ryan Propper_, Sep 27 2006 *)

%Y Cf. A109611.

%K nonn

%O 1,3

%A _Jason Earls_, Sep 04 2005

%E More terms from _Ryan Propper_, Sep 27 2006