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A060443 Table T(n,k) in which n-th row lists prime factors of 2^n - 1 (n >= 2), without repetition. 9
0, 1, 3, 7, 3, 5, 31, 3, 7, 127, 3, 5, 17, 7, 73, 3, 11, 31, 23, 89, 3, 5, 7, 13, 8191, 3, 43, 127, 7, 31, 151, 3, 5, 17, 257, 131071, 3, 7, 19, 73, 524287, 3, 5, 11, 31, 41, 7, 127, 337, 3, 23, 89, 683, 47, 178481, 3, 5, 7, 13, 17, 241 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

For n > 1, the length of row n is A046800(n). - T. D. Noe, Aug 06 2007

REFERENCES

J. Brillhart et al., Factorizations of b^n +- 1. Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 2nd edition, 1985; and later supplements.

LINKS

T. D. Noe, Rows n=0..500 of triangle, flattened (derived from Brillhart et al.)

Joerg Arndt, Rows n=1..1200 of triangle when repetitions are included (derived from Brillhart et al.)

J. Brillhart et al., Factorizations of b^n +- 1, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002.

Jeroen Demeyer, Machine-readable Cunningham Tables [Broken link]

S. S. Wagstaff, Jr., The Cunningham Project

EXAMPLE

From Wolfdieter Lang, Sep 23 2017: (Start)

The irregular triangle T(n,k) begins for n >= 2:

n\k      1   2    3    4   5

2:       3

3:       7

4:       3   5

5:      31

6:       3   7

7:     127

8:       3   5   17

9:       7  73

10:      3  11   31

11:     23  89

12:      3   5    7   13

13:   8191

14:      3  43  127

15:      7  31  151

16:      3   5   17  257

17: 131071

18:      3   7   19   73

19: 524287

20:      3   5   11   31  41

... (End)

CROSSREFS

Cf. A001265, A064078.

Sequence in context: A337013 A122583 A001265 * A020810 A248895 A021732

Adjacent sequences:  A060440 A060441 A060442 * A060444 A060445 A060446

KEYWORD

nonn,tabf

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified November 25 17:54 EST 2020. Contains 338625 sequences. (Running on oeis4.)