> maple

    |\^/|     Maple 7 (DEC ALPHA UNIX)
._|\|   |/|_. Copyright (c) 2001 by Waterloo Maple Inc.
 \  MAPLE  /  All rights reserved. Maple is a registered trademark of
 <____ ____>  Waterloo Maple Inc.
      |       Type ? for help.
> with(qseries);
[aqprod, changes, etamake, etaq, findhom, findhomcombo, findhommodp, findnonhom, 
 findnonhomcombo, findpoly, jac2prod, jac2series, jacprod, jacprodmake, mprodmake, 
 packageversion, prodmake, qbin, qetamake, qfactor, quinprod, sift, theta, theta2, 
 theta3, theta4, tripleprod, winquist, zqfactor]

> x:=add(q^(n*n),n=-10..10);
             100      81      64      49      36      25      16      9      4
 x := 1 + 2 q    + 2 q   + 2 q   + 2 q   + 2 q   + 2 q   + 2 q   + 2 q  + 2 q  + 2 q

> etamake(x,q,20);
                                                         5
                                               eta(2 tau)
                                          ---------------------
                                                    2         2
                                          eta(4 tau)  eta(tau)