OFFSET
0,5
COMMENTS
This theta series is an element of the space of modular forms on Gamma_0(7) of weight 10 and dimension 7. - Andy Huchala, May 15 2023
REFERENCES
J. H. Conway, R. T. Curtis, S. P. Norton, R. A. Parker and R. A. Wilson, ATLAS of Finite Groups. Oxford Univ. Press, 1985 [for best online version see https://oeis.org/wiki/Welcome#Links_to_Other_Sites], p. 39.
LINKS
Andy Huchala, Table of n, a(n) for n = 0..10000
G. Nebe and N. J. A. Sloane, Home page for this lattice
PROG
(Magma)
prec := 30;
gram := [8, 2, 8, -1, 0, 8, 0, -2, 0, 8, 2, -1, -2, 4, 8, -2, 0, -1, -1, -1, 8, -2, -1, 0, -1, -2, 0, 8, 0, -1, 0, -1, -2, -2, -1, 8, 0, 0, -1, -2, -1, 0, 0, -1, 8, 1, 1, 0, 2, 2, 0, 0, 0, 0, 8, 1, 4, 2, -2, -1, -2, -2, 2, -2, 0, 8, -4, -2, 2, 0, 0, 0, -1, -1, 1, 0, -1, 8, 4, 0, -1, 0, 1, -2, 2, 0, -1, -2, 1, -4, 8, -4, 1, 0, -1, 0, -1, 0, 0, -1, -1, 2, 2, 0, 8, -2, -2, -4, 4, 2, 0, 2, -1, -2, 0, -2, 0, 0, -1, 8, 4, 1, -2, 2, 2, 2, -2, -2, -1, -1, -1, -4, 4, -2, 1, 8, 2, -1, -2, -1, 0, 0, -1, -2, -1, -2, -2, -1, 0, -2, 2, 2, 8, -2, 0, 0, -2, -2, -1, 1, 0, 0, -1, 2, 1, -1, 0, 2, -2, 2, 8, 0, 0, -1, -2, -1, 0, 0, 2, 4, -4, -2, -1, 0, -1, -2, 0, 0, 1, 8, 4, 1, -1, -2, 1, -2, 1, -4, 0, -2, 1, -1, 4, 0, 0, 2, 4, 2, -1, 8];
S := SymmetricMatrix(gram);
L := LatticeWithGram(S);
T := ThetaSeriesModularForm(L);
Coefficients(PowerSeries(T, prec)); // Andy Huchala, May 15 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Andy Huchala, May 15 2023
STATUS
approved