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A206001 Least k such that k*2^m + 1 has a covering set with precisely n primes. 1
271129, 78557, 1777613, 169073869 (list; graph; refs; listen; history; text; internal format)
OFFSET

6,1

COMMENTS

a(10) > 2^31. a(11) = 1143502909. - Arkadiusz Wesolowski, Apr 29 2012

LINKS

Table of n, a(n) for n=6..9.

Wikipedia, Covering set

Wikipedia, Sierpinski number

EXAMPLE

271129 has the covering set {3, 5, 7, 13, 17, 241}.

78557 has the covering set {3, 5, 7, 13, 19, 37, 73}.

1777613 has the covering set {3, 5, 7, 13, 17, 19, 109, 433}.

169073869 has the covering set {3, 5, 7, 11, 13, 41, 61, 151, 331}.

CROSSREFS

Cf. A076336.

Sequence in context: A249254 A075467 A257647 * A244561 A137715 A258893

Adjacent sequences:  A205998 A205999 A206000 * A206002 A206003 A206004

KEYWORD

more,nonn

AUTHOR

Arkadiusz Wesolowski, Feb 10 2012

STATUS

approved

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Last modified February 29 05:25 EST 2020. Contains 332353 sequences. (Running on oeis4.)