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Quadratic non-residues of 23: numbers n such that Jacobi(n,23) = -1.
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%I #17 Jan 12 2020 13:59:58

%S 5,7,10,11,14,15,17,19,20,21,22,28,30,33,34,37,38,40,42,43,44,45,51,

%T 53,56,57,60,61,63,65,66,67,68,74,76,79,80,83,84,86,88,89,90,91,97,99,

%U 102,103,106,107,109,111,112,113,114,120,122,125,126,129,130,132,134,135,136,137,143,145,148,149

%N Quadratic non-residues of 23: numbers n such that Jacobi(n,23) = -1.

%C Important for the study of Ramanujan numbers A000594.

%D Wilton, John Raymond. "Congruence properties of Ramanujan's function τ(n)." Proceedings of the London Mathematical Society 2.1 (1930): 1-10. See page 1.

%H <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1).

%F From _Robert Israel_, Nov 30 2016: (Start)

%F a(n+11) = a(n)+23.

%F G.f.: (x^11+x^10+x^9+x^8+2*x^7+2*x^6+x^5+3*x^4+x^3+3*x^2+2*x+5)/(x^12-x^11-x+1). (End)

%t LinearRecurrence[{1,0,0,0,0,0,0,0,0,0,1,-1},{5,7,10,11,14,15,17,19,20,21,22,28},80] (* _Harvey P. Dale_, Jan 12 2020 *)

%Y Cf. A028736, A000594, A063987, A278580.

%Y For the primes in this sequence see A191065.

%K nonn

%O 1,1

%A _N. J. A. Sloane_, Nov 29 2016