[Jtsummers]

Re edit: Put a space between the * and the characters.

  5 * N

versus

  5*N

Pairs of asterisks adjacent to non-space characters become markers indicating italicized text.

  5*N is easier to remember than 16*N

5N is easier to remember than 16N

Versus

  5 * N is easier to remember than 16 * N

5 * N is easier to remember than 16 * N

And I think the word you want is exponential, not logarithmic. Related to each other, since exponential expressions become linear on a logarithmic scale, but exponential describes the growth of 2^n better.