## Functiones et Approximatio Commentarii Mathematici

### Evaluation of the convolution sum $\sum_{al+bm=n} \sigma(l) \sigma(m)$ for $(a,b)=(1,48),(3,16),(1,54),(2,27)$

Title: Evaluation of the convolution sum $\sum_{al+bm=n} \sigma(l) \sigma(m)$ for $(a,b)=(1,48),(3,16),(1,54),(2,27)$