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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A136582 Sqrt(10)-primes: primes obtained by concatenating the first digits in the decimal expansion of sqrt(10). 6
3, 31, 3162277, 316227766016837933, 316227766016837933199889354443271 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

n such that floor(sqrt(10^(2*n-1))) is prime (1, 2, 7, 18, 33,  ...) are given in A136583.

This sequence is the list of prime terms in A017934.

FORMULA

a(n) = A017934(2*A136583(n)-1).

PROG

(MAGMA) // by Jason Kimberley, Aug 2011

for n in [1..499 by 2] do

  f := Isqrt(10^n);

  if IsPrime(f) then

    printf "%o, ", f;

  end if;

end for;

CROSSREFS

Cf. A010467, A017934, A017934, A131581, A132153, A136583, A175733, A175734.

Sequence in context: A168678 A118913 A005042 * A173649 A119937 A197368

Adjacent sequences:  A136579 A136580 A136581 * A136583 A136584 A136585

KEYWORD

nonn,base

AUTHOR

Lekraj Beedassy (blekraj(AT)yahoo.com), Jan 09 2008

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 16 01:31 EST 2012. Contains 205860 sequences.