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 A038897 23 is a square mod p. 2
 2, 7, 11, 13, 19, 23, 29, 41, 43, 67, 73, 79, 83, 101, 103, 107, 173, 191, 193, 197, 199, 227, 233, 251, 257, 263, 269, 277, 283, 317, 349, 353, 359, 367, 379, 383, 397, 409, 419, 431, 449, 461, 467, 479, 503, 509 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Also, only entries p=1 (mod 4) of the sequence are squares mod 23 (from the quadratic reciprocity law). - Lekraj Beedassy, Jul 21 2004 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 MATHEMATICA Select[Prime[Range[100]], JacobiSymbol[23, #] != -1 &] (* Vincenzo Librandi, Sep 07 2012 *) CROSSREFS Sequence in context: A191052 A138889 A097143 * A161681 A020583 A140557 Adjacent sequences:  A038894 A038895 A038896 * A038898 A038899 A038900 KEYWORD nonn AUTHOR STATUS approved

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Last modified December 6 07:04 EST 2019. Contains 329784 sequences. (Running on oeis4.)