Function: mfderivE2
Section: modular_forms
C-Name: mfderivE2
Prototype: GD1,L,
Help: mfderivE2(F,{m=1}): compute the Serre derivative (q.d/dq)F - kE_2F/12
 of the generalized modular form F of weight k; and if m > 1, the m-th iterate.
Doc: compute the Serre derivative $(q \* d/dq)F - kE_{2}F/12$
 of the generalized modular form $F$, which has weight $k+2$;
 if $F$ is a true modular form, then its Serre derivative is also modular.
 If $m>1$, compute the $m$-th iterate, of weight $k + 2m$.
 \bprog
 ? mfcoefs(mfderivE2(mfEk(4)),5)*(-3)
 %1 = [1, -504, -16632, -122976, -532728]
 ? mfcoefs(mfEk(6),5)
 %2 = [1, -504, -16632, -122976, -532728]
 @eprog
