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 A038922 Primes p such that 42 is not a square mod p. 2
 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 A082283 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

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Last modified September 7 13:22 EDT 2024. Contains 375730 sequences. (Running on oeis4.)