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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
Amiram Eldar, Table of n, a(n) for n = 2..626 (terms 2..200 from Vincenzo Librandi)
FORMULA
a(n) = A006530(A036563(n)). - Amiram Eldar, Sep 12 2022
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
Sequence in context: A023619 A020576 A093810 * A120274 A036982 A029580
KEYWORD
nonn
AUTHOR
Yasutoshi Kohmoto, May 11 2004
EXTENSIONS
More terms from Robert G. Wilson v, May 24 2004
STATUS
approved

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Last modified March 29 09:44 EDT 2024. Contains 371268 sequences. (Running on oeis4.)