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Primes for which the level as defined in A117563 is 3.
5

%I #7 Oct 31 2013 12:17:38

%S 11,19,37,43,97,113,127,139,163,223,307,313,317,337,389,397,401,421,

%T 457,479,547,673,691,709,757,761,853,863,883,929,937,953,1021,1051,

%U 1109,1297,1303,1327,1399,1471,1567,1571,1583,1693,1699,1723,1783,1951,2029

%N Primes for which the level as defined in A117563 is 3.

%H Remi Eismann, <a href="/A117873/b117873.txt">Table of n, a(n) for n = 1..10000</a>

%e 13 = 11 + 11 mod 3 = 11 + 11 mod 9, level = 3

%e 701 = 691 + 691 mod 227 = 691 + 691 mod 681, level = 3

%e 6907 = 6899 + 6899 mod 2297 = 6899 + 6899 mod 6891, level = 3

%t f[n_] := Block[{d, j = 2, p = Prime@n}, d = Prime[n + 1] - p; While[j < p && Mod[p, j] != d, j++ ]; If[j == p, 0, j]]; g[n_] := Block[{d, k = p = Prime@n}, d = Prime[n + 1] - p; While[k > 0 && Mod[p, k] != d, k-- ]; If[k == 0, 0, k]]; h[n_] := Block[{a = f@n, b = g@n}, If[a == 0, 0, b/a]]; Prime@Select[ Range@327, h@# == 3 &] (* _Robert G. Wilson v_ *)

%Y Cf. A117563, A117078, A118534.

%K nonn

%O 1,1

%A _RĂ©mi Eismann_, May 02 2006

%E More terms from _Robert G. Wilson v_, May 06 2006