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%I #15 Sep 03 2020 19:23:40
%S 1,4,5,7,9,11,16,17,19,20,23,25,28,35,36,43,44,45,47,49,55,61,63,64,
%T 68,73,76,77,80,81,83,85,92,95,99,100,101,112,115,119,121,125,131,133,
%U 137,139,140,144,149,153,157,161,163,169,171,172,175,176,180,187,188,191,196,197,199,207,209,215,220,225,229,233,235,239,244,245,251,252,253,256
%N Positive numbers of the form x^2+xy+5y^2 (discriminant -19).
%C Indices of nonzero terms in expansion of Dirichlet series Product_p (1-(Kronecker(m,p)+1)*p^(-s)+Kronecker(m,p)*p^(-2s))^(-1) for m= -19 (A035171). [amended by _Georg Fischer_, Sep 03 2020]
%o (PARI) m=-19; select(x -> x, direuler(p=2,101,1/(1-(kronecker(m,p)*(X-X^2))-X)), 1) \\ Fixed by _Andrey Zabolotskiy_, Sep 03 2020
%Y Cf. A035171.
%Y For primes see A106863.
%K nonn
%O 1,2
%A _N. J. A. Sloane_
%E Edited by _N. J. A. Sloane_, Jun 01 2014
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