The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A157145 Prime numbers containing an equal, nonzero number of odd nonprime digits and of even prime digits. 1
29, 127, 239, 241, 251, 269, 271, 281, 293, 421, 521, 821, 829, 1229, 1237, 1277, 1283, 1327, 1423, 1427, 1523, 1627, 1723, 1823, 2017, 2039, 2069, 2081, 2089, 2129, 2137, 2143, 2153, 2309, 2339, 2341, 2351, 2371, 2381, 2389, 2393, 2417, 2441, 2459, 2531 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Even prime digit = 2. Odd nonprime digits are 1 or 9.
LINKS
MATHEMATICA
onpdQ[n_]:=Module[{od=DigitCount[n, 10, 1]+DigitCount[n, 10, 9], ev= DigitCount[ n, 10, 2]}, od==ev>0]; Select[Prime[Range[400]], onpdQ] (* Harvey P. Dale, Aug 11 2019 *)
CROSSREFS
Cf. A000040.
Sequence in context: A287406 A233114 A264672 * A142438 A342823 A118097
KEYWORD
nonn,base,less
AUTHOR
EXTENSIONS
Definition corrected and terms 2069..2089 inserted by R. J. Mathar, May 15 2010
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 May 14 05:21 EDT 2024. Contains 372528 sequences. (Running on oeis4.)