login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A033699
Theta series of lattice A_2 tensor E_7 (dimension 14, determinant 8748, minimal norm 4).
2
1, 0, 378, 4032, 24948, 84672, 272706, 689472, 1471554, 3003840, 6041952, 9640512, 17409420, 28304640, 42284052, 64338624, 101413620, 131362560, 198388554, 275679936, 359236080, 484706880, 685716192, 805569408, 1113880362, 1430763264, 1734830244, 2189464704
OFFSET
0,3
COMMENTS
Theta series is an element of the space of modular forms on Gamma_1(6) with Kronecker character -3 in modulus 6, weight 7, and dimension 8 over the integers. - Andy Huchala, May 13 2023
LINKS
G. Nebe and N. J. A. Sloane, Home page for this lattice
EXAMPLE
G.f. = 1 + 378*q^4 + 4032*q^6 + ...
PROG
(Magma)
prec := 20;
ls := [[4, -2, -2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [-2, 4, 1, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [-2, 1, 4, -2, -2, 1, 0, 0, 0, 0, 0, 0, 0, 0], [1, -2, -2, 4, 1, -2, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, -2, 1, 4, -2, -2, 1, 0, 0, 0, 0, 0, 0], [0, 0, 1, -2, -2, 4, 1, -2, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, -2, 1, 4, -2, -2, 1, 0, 0, -2, 1], [0, 0, 0, 0, 1, -2, -2, 4, 1, -2, 0, 0, 1, -2], [0, 0, 0, 0, 0, 0, -2, 1, 4, -2, -2, 1, 0, 0], [0, 0, 0, 0, 0, 0, 1, -2, -2, 4, 1, -2, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, -2, 1, 4, -2, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 1, -2, -2, 4, 0, 0], [0, 0, 0, 0, 0, 0, -2, 1, 0, 0, 0, 0, 4, -2], [0, 0, 0, 0, 0, 0, 1, -2, 0, 0, 0, 0, -2, 4]];
S := Matrix(ls);
L := LatticeWithGram(S);
M := ThetaSeriesModularFormSpace(L);
B := Basis(M, prec);
coeffs := [1, 0, 378, 4032, 24948, 84672, 272706, 689472];
Coefficients(&+[coeffs[i]*B[i] :i in [1..8]]); // Andy Huchala, May 13 2023
CROSSREFS
Sequence in context: A235761 A154078 A047632 * A235544 A325848 A248915
KEYWORD
nonn
AUTHOR
EXTENSIONS
Edited by N. J. A. Sloane Aug 31 2009 at the suggestion of R. J. Mathar
More terms from Andy Huchala, May 13 2023
STATUS
approved