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A093810 Smallest prime factor of 2^n-3. 2

%I

%S 1,5,13,29,61,5,11,509,1021,5,4093,19,16381,5,13,53,11,5,1048573,773,

%T 4194301,5,16777213,479,37,5,11,536870909,23,5,9241,29,5113,5,242819,

%U 47189,11,5,13,23,47,5,5927,2087,227,5,11,19,59,5,13,2203,36217,5,181

%N Smallest prime factor of 2^n-3.

%H Vincenzo Librandi, <a href="/A093810/b093810.txt">Table of n, a(n) for n = 2..200</a>

%t PrimeFactors[n_] := Flatten[ Table[ # [[1]], {1}] & /@ FactorInteger[n]]; Table[ PrimeFactors[2^n - 3][[1]], {n, 2, 60}] (* _Robert G. Wilson v_, May 24 2004 *)

%t FactorInteger[#][[1,1]]&/@(2^Range[2,60]-3) (* _Harvey P. Dale_, Aug 21 2016 *)

%Y Cf. A093817, A050414, A050415.

%K nonn

%O 2,2

%A _Yasutoshi Kohmoto_, May 11 2004

%E More terms from _Robert G. Wilson v_, May 24 2004

%E Typo in Mathematica code corrected by _Vincenzo Librandi_, May 14 2013

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Last modified February 18 20:04 EST 2019. Contains 320262 sequences. (Running on oeis4.)