If the decedent leaves no surviving spouse, but there is a child or children and the lawful issue of a child or children, the estate goes to the child or children and lawful issue of the child or children by right of representation as follows: To the child or children, each a share and to the lawful issue of each deceased child, by right of representation, the same share that the parent would have received if the parent had been living at the time of the death of the decedent.