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%I #19 Nov 21 2013 12:46:44
%S 3,3,2,3,19,5,13,7,17,19,43,11,103,13,29,31,67,17,37,19,41,43,367,23,
%T 199,103,53,223,463,29,61,31,131,67,139,71,73,37,311,79,163,41,5503,
%U 43,89,367,751,47,97,199,101,103,211,53,109,223,113,463,241663,59,487,61
%N Smallest prime of form n*2^m-1, m >= 0, or 0 if no such prime exists.
%H Reinhard Zumkeller, <a href="/A038699/b038699.txt">Table of n, a(n) for n = 1..650</a>
%t getm[n_]:=Module[{m=0},While[!PrimeQ[n 2^m-1],m++];n 2^m-1]; Array[getm,80] (* _Harvey P. Dale_, Apr 24 2011 *)
%o (Haskell)
%o a038699 = until ((== 1) . a010051) ((+ 1) . (* 2)) . (subtract 1)
%o -- _Reinhard Zumkeller_, Mar 05 2012
%Y Primes arising in A040081 (or 0 if no prime exists).
%Y Cf. A040081, A050921.
%Y Cf. A010051, A000079.
%K nonn,easy,nice
%O 1,1
%A _N. J. A. Sloane_, Dec 30 1999
%E More terms from _Henry Bottomley_, Apr 24 2001
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