  We give formulas for the image Milnor number of a weighted-homogeneous
map-germ $(\mathbb{C}^n,0)\to(\mathbb{C}^{n+1},0)$, for $n=4$ and $5$, in terms
of weights and degrees. Our expressions are obtained by a purely interpolative
method, applied to a result by Ohmoto. We use our approach to recover the
formulas for $n=2$ and $3$ due to Mond and Ohmoto, respectively. For $n\geq 6$,
the method is valid as long as certain multi-singularity conjecture holds.
