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A093817 Largest prime factor of 2^n-3. 2
1, 5, 13, 29, 61, 5, 23, 509, 1021, 409, 4093, 431, 16381, 6553, 71, 2473, 23831, 97, 1048573, 2713, 4194301, 1677721, 16777213, 70051, 5197, 31033, 1877171, 536870909, 46684427, 22605091, 464773, 296204641, 3360037, 6871947673, 283007 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 2..200

MATHEMATICA

PrimeFactors[n_] := Flatten[ Table[ # [[1]], {1}] & /@ FactorInteger[n]]; Table[ PrimeFactors[2^n - 3][[ -1]], {n, 2, 46}] (* Robert G. Wilson v, May 24 2004 *)

Table[FactorInteger[2^n-3][[-1, 1]], {n, 2, 40}] (* Harvey P. Dale, Feb 01 2015 *)

CROSSREFS

Cf. A093810, A050414, A050415.

Sequence in context: A023619 A020576 A093810 * A120274 A036982 A029580

Adjacent sequences:  A093814 A093815 A093816 * A093818 A093819 A093820

KEYWORD

nonn

AUTHOR

Yasutoshi Kohmoto, May 11 2004

EXTENSIONS

More terms from Robert G. Wilson v, May 24 2004

Typo in Mathematica code corrected by Vincenzo Librandi, May 14 2013

STATUS

approved

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Last modified February 24 17:22 EST 2018. Contains 299624 sequences. (Running on oeis4.)