login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A020463 Primes that contain digits 3 and 7 only. 9
3, 7, 37, 73, 337, 373, 733, 773, 3373, 3733, 7333, 33377, 33773, 37337, 77377, 77773, 333337, 333737, 373777, 377737, 733333, 733373, 737773, 773777, 777373, 777737, 3333373, 3333773, 3337333, 3337777, 3377377, 3733333, 3773377, 3773773, 3777377 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

MathOverflow, 3-7 primes in base 10

MATHEMATICA

Flatten[Table[Select[FromDigits/@Tuples[{3, 7}, n], PrimeQ], {n, 7}]] (* Vincenzo Librandi, Jul 27 2012 *)

CROSSREFS

A143967, A020458. [From Reinhard Zumkeller, Sep 06 2008]

Sequence in context: A260382 A260381 A260378 * A057625 A308392 A087208

Adjacent sequences:  A020460 A020461 A020462 * A020464 A020465 A020466

KEYWORD

nonn,base

AUTHOR

David W. Wilson

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 25 10:10 EDT 2019. Contains 324351 sequences. (Running on oeis4.)