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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A038922 Primes p such that 42 is not a square mod p. 1
5, 23, 31, 37, 43, 59, 67, 71, 73, 83, 97, 101, 103, 109, 113, 131, 137, 163, 173, 191, 199, 211, 223, 227, 233, 239, 241, 251, 263, 269, 271, 277, 281, 293, 313, 331, 359, 367, 373, 379, 401, 409, 419, 421, 431 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

MATHEMATICA

Select[Prime@Range[120], JacobiSymbol[42, #] == -1 &] (* Vincenzo Librandi, Sep 09 2012 *)

PROG

(PARI) select(n->!issquare(Mod(42, n)), primes(100)) \\ Charles R Greathouse IV, Sep 09 2012

(MAGMA) [p: p in PrimesUpTo(431) | not IsSquare(R! 42) where R:= ResidueClassRing(p)]; // Vincenzo Librandi, Sep 10 2012

(MAGMA) [p: p in PrimesInInterval(3, 431) | JacobiSymbol(42, p) eq -1]; // Bruno Berselli, Sep 10 2012

CROSSREFS

Sequence in context: A140386 A105880 A163587 * A019367 A065867 A071199

Adjacent sequences:  A038919 A038920 A038921 * A038923 A038924 A038925

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Offset changed from 0 to 1 by Vincenzo Librandi, Sep 09 2012

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 July 19 12:35 EDT 2019. Contains 325159 sequences. (Running on oeis4.)