A032728 - OEIS

%I #16 Aug 13 2024 11:13:30

%S 4,5,7,8,10,11,16,20,22,25,29,31,32,35,38,44,46,49,52,53,55,65,70,71,

%T 73,76,77,88,91,92,98,101,103,106,107,113,115,118,121,124,125,131,137,

%U 146,148,164,169,172,176,179,184,185,200,202,205,206,208,209,211

%N Numbers k such that k prefixed by '3' and followed by '9' is prime.

%H Harvey P. Dale, <a href="/A032728/b032728.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Range[250],PrimeQ[FromDigits[Join[{3},IntegerDigits[#],{9}]]]&] (* _Harvey P. Dale_, Aug 17 2021 *)

%Y Cf. A032702-A032733.

%K nonn,base

%O 1,1

%A _Patrick De Geest_, May 15 1998

%E Offset changed by _Andrew Howroyd_, Aug 13 2024