OFFSET
0,3
LINKS
G. Nebe and N. J. A. Sloane, Home page for this lattice
EXAMPLE
G.f. = 1 + 6*x^2 + 12*x^4 + 12*x^5 + 6*x^6 + 24*x^7 + 18*x^8 + 24*x^10 + ...
G.f. = 1 + 6*q^4 + 12*q^8 + 12*q^10 + 6*q^12 + 24*q^14 + 18*q^16 + 24*q^20 + ...
PROG
(PARI) {a(n) = if( n<0, 0, polcoeff( 1 + 2 * x * Ser( qfrep( [4, 2, 2, 1; 2, 4, 1, 2; 2, 1, 8, 4; 1, 2, 4, 8], n, 1)), n))};
(Magma) A := Basis( ModularForms( Gamma0(21), 2), 64); A[1] + 6*A[3];
CROSSREFS
KEYWORD
nonn
AUTHOR
Michael Somos, Apr 12 2015
STATUS
approved