A093817 Largest prime factor of 2^n-3.
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
Offset: 2
Keywords
Links
- Amiram Eldar, Table of n, a(n) for n = 2..626 (terms 2..200 from Vincenzo Librandi)
Programs
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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 *)
Formula
Extensions
More terms from Robert G. Wilson v, May 24 2004