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%I #7 Jul 15 2012 09:11:10
%S 5,11,17,509,29,83,41,79,887,59,109,71,331,193,383,190717,101,107,787,
%T 277,1129,911,137,1181,149,463,1013,839,1087,179,433,191,197,4093,349,
%U 503,2423,227,701,239,5378731,587,601,439,269,6491,281,1621,877,499
%N Least prime of level 2n-1 (cf. A117563).
%F Levels of primes are defined in A117563. Conjecture: there are an infinite number of prime members at each level.
%e The first occurrence of 1 in A117563 is a(3) which implies the third prime which is 5.
%e The first occurrence of 3 in A117562 is a(5) which implies the fifth prime which is 11.
%e The first occurrence of 5 in A117562 is a(7) which implies the seventh prime which is 17, etc.
%t f[n_] := If[n == 1, 0, Block[{p = Prime@n, np = Prime[n + 1]}, (2p - np)/Min@Select[Divisors[2p - np], # >= np - p &]]]; t = Table[0, {100}]; Do[a = (f@n + 1)/2; If[a < 101 && t[[a]] == 0, t[[a]] = Prime@n; Print[{a, n, Prime@n}]], {n, 10^6}]
%Y Cf. A117078, A117563, A117873, A117874, A118481, A118508.
%K nonn
%O 1,1
%A _Rémi Eismann_ and _Robert G. Wilson v_, May 12 2006
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