A015165 Theta series of 17-dimensional lattice Q'_17(6)^{+6}.

1, 0, 0, 0, 0, 0, 0, 0, 102, 136, 0, 1632, 1326, 0, 9792, 8160, 0, 36144, 31552, 0, 122196, 88128, 0, 394944, 240618, 0, 992256, 658784, 0, 1991040, 1452480, 0, 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

Offset

0,9

Links

Table of n, a(n) for n=0..70.

J. H. Conway and N. J. A. Sloane, Low-Dimensional Lattices II: Subgroups of GL(n,Z), Proc. Royal Soc. London, A 419 (1988), 29-68.

Gheorghe Coserea, Gram matrix.

G. Nebe and N. J. A. Sloane, Home page for this lattice

W. Plesken, Finite Unimodular Groups of Prime Degree and Circulants, J. Algebra, vol. 97 (1985), pp. 286-312.

Prog

(PARI) \\ system("wget https://oeis.org/A015165/a015165.txt");
g = matconcat(read("a015165.txt")~);
seq(N, g, flag=0) = concat(1, 2*Vec(qfrep(g, N, flag)));
seq(33, g) \\ Gheorghe Coserea, Nov 28 2018
(PARI)
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])}
a(n)={if(n==0, 1, 2*qfrep(GramMatrix(), n, 0)[n])} \\ Andrew Howroyd, Nov 29 2018

Crossrefs

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

Sequence in context: A107838 A095637 A023059 * A160918 A145578 A318792

Adjacent sequences: A015162 A015163 A015164 * A015166 A015167 A015168

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Gheorghe Coserea, Nov 28 2018

Status

approved