How do I take a Grand sum of a nth dimensional matrix

edit

I'm new to sage so cut me some slack if what I ask sounds uneducated. currently what I'm trying to do is take the tensor product of [z^2+c] over and over than take the grand sum. so like the sum of all elements in the nth dimensional matrix [z^2+c]⊗[z^2+c]⊗[z^2+c]⊗,.... Lim n->∞ oh also I need help with using tensor products yeah I just thought I should ask about the grand sum first, sorry if I sound dumb.