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[3200], Min @ Complement[Range[# - 1], Mod[Range[#/2]^2, #]] == 7 &] (* 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
isA025023(n)=residue(2, n) && residue(3, n) && residue(5, n) && !residue(7, n) \\ Michael B. Porter, Apr 19 2010
(PARI) is(n)=issquare(Mod(2, n)) && issquare(Mod(3, n)) && issquare(Mod(5, n)) && !issquare(Mod(7, n)) \\ Charles R Greathouse IV, Jan 24 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved