login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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
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
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, May 15 1998
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 11:14 EDT 2024. Contains 371278 sequences. (Running on oeis4.)