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A104052 Primes of the form 2^k-5^m, where 2^k/5^m < 2. 1
3, 7, 971, 18280739 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The current entries are generated by (k=3,m=1) or (k=7,m=3), (k=5,m=2), (k=12,m=5) and (k=26,m=11). Another term with 110 digits is created by (k=367,m=158) and an entry with 199 digits by (k=662,m=285). - R. J. Mathar, Feb 13 2013

LINKS

Table of n, a(n) for n=1..4.

MATHEMATICA

c = Delete[Union[Flatten[Table[Table[If [ (2^n > 5^m) && Floor[2^n/5^m] < 2, Abs[2^n - 5^m], 0], {m, 1, n}], {n, 1, 200}], 1]], 1] d = Delete[Union[Table[If[PrimeQ[c[[n]]], c[[n]], 0], {n, 1, Length[c]}]], 1]

CROSSREFS

Sequence in context: A055624 A065244 A012844 * A062625 A175986 A296351

Adjacent sequences: A104049 A104050 A104051 * A104053 A104054 A104055

KEYWORD

nonn

AUTHOR

Roger L. Bagula, Mar 01 2005

STATUS

approved

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Last modified November 28 03:39 EST 2022. Contains 358406 sequences. (Running on oeis4.)