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 A035269 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= 41. 1

%I

%S 1,2,4,5,8,9,10,16,18,20,23,25,31,32,36,37,40,41,43,45,46,49,50,59,61,

%T 62,64,72,73,74,80,81,82,83,86,90,92,98,100,103,107,113,115,118,121,

%U 122,124,125,127,128,131,139,144,146,148,155,160,162,163,164

%N 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= 41.

%C Also, positive numbers represented by 2x^2+3xy-4y^2, discriminant 41.

%C The PARI code gives the sequence A035223: 1, 2, 0, 3, 2, 0, 0, 4, 1, 4, 0, ... - _Colin Barker_, Jun 18 2014

%H N. J. A. Sloane et al., <a href="https://oeis.org/wiki/Binary_Quadratic_Forms_and_OEIS">Binary Quadratic Forms and OEIS</a> (Index to related sequences, programs, references)

%t Reap[For[n = 0, n <= 100, n++, If[Reduce[ 2*x^2 + 3*x*y - 4*y^2 == n, {x, y}, Integers] =!= False, Sow[n]]]][[2, 1]] - _N. J. A. Sloane_, Jun 05 2014

%o (PARI) direuler(p=2,101,1/(1-(kronecker(m,p)*(X-X^2))-X))

%Y Primes: A141181.

%Y Cf. A035223.

%K nonn

%O 1,2

%A _N. J. A. Sloane_.

%E More terms from _Colin Barker_, Jun 17 2014

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Last modified December 12 00:07 EST 2018. Contains 318052 sequences. (Running on oeis4.)