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Theta series of 17-dimensional lattice Q'_17(6)^{+6}.
8

%I #25 Dec 07 2018 12:31:04

%S 1,0,0,0,0,0,0,0,102,136,0,1632,1326,0,9792,8160,0,36144,31552,0,

%T 122196,88128,0,394944,240618,0,992256,658784,0,1991040,1452480,0,

%U 4163742,2622216,0,9238752,5030028,0,17109888,10390944,0,26670144,18128256,0,45317988,26822464,0,84237312,43527174,0,134013312,77769696,0,183149568,119299200,0,276648888,157895592,0,463739328,232127928,0,672628800,379052672,0,845519616,537564480,0,1186603368,662425536,0

%N Theta series of 17-dimensional lattice Q'_17(6)^{+6}.

%H J. H. Conway and N. J. A. Sloane, <a href="https://www.jstor.org/stable/2398331">Low-Dimensional Lattices II: Subgroups of GL(n,Z)</a>, Proc. Royal Soc. London, A 419 (1988), 29-68.

%H Gheorghe Coserea, <a href="/A015165/a015165.txt">Gram matrix</a>.

%H G. Nebe and N. J. A. Sloane, <a href="http://www.math.rwth-aachen.de/~Gabriele.Nebe/LATTICES/Qp1766.html">Home page for this lattice</a>

%H W. Plesken, <a href="https://core.ac.uk/download/pdf/82549703.pdf">Finite Unimodular Groups of Prime Degree and Circulants</a>, J. Algebra, vol. 97 (1985), pp. 286-312.

%o (PARI) \\ system("wget https://oeis.org/A015165/a015165.txt");

%o g = matconcat(read("a015165.txt")~);

%o seq(N, g, flag=0) = concat(1, 2*Vec(qfrep(g, N, flag)));

%o seq(33, g) \\ _Gheorghe Coserea_, Nov 28 2018

%o (PARI)

%o GramMatrix()={my(p=[11, 2, 2, -4, -4, -7, -1, 2, 5, 5, 2, -1, -7, -4, -4, 2, 2]); matrix(#p, #p, i, j, p[(i-j) %#p + 1])}

%o a(n)={if(n==0, 1, 2*qfrep(GramMatrix(), n, 0)[n])} \\ _Andrew Howroyd_, Nov 29 2018

%Y Cf. A015158, A015159, A015160, A015161, A015162, A015163, A015164.

%K nonn

%O 0,9

%A _N. J. A. Sloane_

%E More terms from _Gheorghe Coserea_, Nov 28 2018