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A280083 Numbers n such that (2^n + 1)/(2 - (-1)^n) is a prime. 1
0, 2, 3, 4, 5, 7, 8, 11, 13, 16, 17, 19, 23, 31, 43, 61, 79, 101, 127, 167, 191, 199, 313, 347, 701, 1709, 2617, 3539, 5807, 10501, 10691, 11279, 12391, 14479, 42737, 83339, 95369, 117239, 127031, 138937, 141079, 267017, 269987, 374321, 986191, 4031399 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..46.

MATHEMATICA

Select[Range[0, 10^3], PrimeQ[(2^# + 1)/(2 - (-1)^#)] &] (* Michael De Vlieger, Dec 25 2016 *)

CROSSREFS

Cf. A000978, A019434.

Sequence in context: A162721 A176176 A174090 * A020902 A008751 A029002

Adjacent sequences:  A280080 A280081 A280082 * A280084 A280085 A280086

KEYWORD

nonn

AUTHOR

Thomas Ordowski, Dec 25 2016

STATUS

approved

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Last modified September 30 05:03 EDT 2020. Contains 337435 sequences. (Running on oeis4.)