was@form:~$ magma
Magma V2.12-10    Wed Sep 28 2005 16:12:13 on form     [S
3818619903]
Type ? for help.  Type <Ctrl>-D to quit.

Loading startup file "/home/was/magma/local/init.m"

> M := ModularSymbols(37);
> M;
Full modular symbols space for Gamma_0(37) of weight 2 ann 5 over Rational Field
> HeckeOperator(M,13);
[-3 -1 -1  1  0]
[-1 -3 -1  0  0]
[ 0  0 -2 -1  0]
[ 0  0  0 -4  0]
[ 0  0  0  6 14]
> M := ModularSymbols(37,2,1);
> HeckeOperator(M,13);
[-2 -1  0]
[ 0 -4  0]
[ 0  6 14]
> Factorisation(CharacteristicPolynomial(HeckeOperator(M,
[
<x - 14, 1>,
<x + 2, 1>,
<x + 4, 1>
]
>