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A025026 Numbers whose least quadratic nonresidue (A020649) is 17. 10
1559, 2999, 3118, 5998, 6551, 8089, 8761, 13102, 13729, 14759, 16178, 16631, 17522, 18119, 19009, 21121, 21961, 23399, 24049, 27431, 27458, 27551, 28081, 29518, 31249, 33262, 33289, 33479, 35281, 35591, 36238, 36791, 38018, 42242, 43391, 43922, 43991 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Quadratic Nonresidue.

MATHEMATICA

Select[Range[20000], Min @ Complement[Range[# - 1], Mod[Range[#/2]^2, #]] == 17 &] (* Amiram Eldar, Oct 31 2020 *)

PROG

(PARI) residue(n, m)=local(r); r=0; for(i=1, floor(m/2), if(i^2%m==n, r=1)); r

isA025026(n)={local(a); a=1; forprime(p=2, 13, a=a && residue(p, n)); a=a && !residue(17, n); a \\ Michael B. Porter, Apr 30 2010

(PARI) is(n)=issquare(Mod(2, n)) && issquare(Mod(3, n)) && issquare(Mod(5, n)) && issquare(Mod(7, n)) && issquare(Mod(11, n)) && issquare(Mod(13, n)) && !issquare(Mod(17, n)) \\ Charles R Greathouse IV, Jan 24 2020

CROSSREFS

Cf. A020649, A025020, A025021, A025022, A025023, A025024, A025025, A025027, A025028, A025029.

Sequence in context: A252321 A252314 A186393 * A343867 A302057 A092001

Adjacent sequences:  A025023 A025024 A025025 * A025027 A025028 A025029

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified October 6 00:49 EDT 2022. Contains 357261 sequences. (Running on oeis4.)