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!)
A156059 Composite numbers whose binary representation reads as decimal prime. 2

%I #12 Jun 29 2013 13:55:36

%S 185,247,253,295,329,355,405,425,453,471,533,539,565,583,595,671,675,

%T 689,703,755,781,785,815,841,855,925,989,1037,1075,1099,1113,1121,

%U 1159,1189,1207,1219,1269,1287,1305,1329,1341,1403,1413,1441,1473,1521,1541

%N Composite numbers whose binary representation reads as decimal prime.

%H Vincenzo Librandi, <a href="/A156059/b156059.txt">Table of n, a(n) for n = 1..1000</a>

%e 185 is composite & 10111001 is prime.

%e 313 is not in the sequence as it is prime in base 10.

%t Select[Range[2900], ! PrimeQ[#]&&PrimeQ[FromDigits[IntegerDigits[#, 2]]]&] (* _Vincenzo Librandi_, Apr 18 2013 *)

%Y Cf. A065720, A007088, A036952.

%K nonn,base

%O 1,1

%A _Gerald Hillier_, Feb 03 2009

%E More terms from _R. J. Mathar_, Feb 10 2009

%E Edited by _N. J. A. Sloane_, Mar 17 2010

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 9 19:33 EDT 2024. Contains 372354 sequences. (Running on oeis4.)