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A032727 Numbers n such that n prefixed by '2' and followed by '9' is prime. 1
2, 3, 6, 12, 17, 23, 26, 30, 33, 38, 39, 45, 53, 54, 57, 60, 65, 68, 69, 71, 72, 74, 78, 81, 87, 90, 93, 96, 99, 101, 105, 108, 113, 114, 116, 117, 126, 131, 137, 141, 149, 152, 155, 156, 158, 159, 164, 173, 179, 183, 185, 192, 203, 207, 210, 212, 215, 218, 222 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

MATHEMATICA

Select[Range[300], PrimeQ[FromDigits[Join[{2}, IntegerDigits[#], {9}]]]&] (* Harvey P. Dale, Apr 02 2017 *)

CROSSREFS

Sequence in context: A200175 A286906 A125867 * A323392 A174801 A324177

Adjacent sequences:  A032724 A032725 A032726 * A032728 A032729 A032730

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, May 15 1998

STATUS

approved

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Last modified December 6 09:43 EST 2021. Contains 349563 sequences. (Running on oeis4.)