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A032727 Numbers n such that n prefixed by '2' and followed by '9' is prime. 1

%I

%S 2,3,6,12,17,23,26,30,33,38,39,45,53,54,57,60,65,68,69,71,72,74,78,81,

%T 87,90,93,96,99,101,105,108,113,114,116,117,126,131,137,141,149,152,

%U 155,156,158,159,164,173,179,183,185,192,203,207,210,212,215,218,222

%N Numbers n such that n prefixed by '2' and followed by '9' is prime.

%H Harvey P. Dale, <a href="/A032727/b032727.txt">Table of n, a(n) for n = 1..1000</a>

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

%K nonn,base

%O 1,1

%A _Patrick De Geest_, May 15 1998

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Last modified January 20 23:47 EST 2022. Contains 350473 sequences. (Running on oeis4.)