Can you get blackboard letter N, R, etc., symbols for mathematical notation? The Special Characters palette includes many mathematical symbols, but I cannot seem to find blackboard bold versions of N, R, and Z, which are commonly used to denote the set of (respectively) the natural numbers, real numbers, and integers.

Right now, when I use the Special Characters palette and configure the Unicode section, and then look for the mathematical symbols, I find blackboard versions of A, B, and others, but inexplicably, certain characters including the N, R, and Z are missing. Here is a screenshot to show what I mean:



Are the blackboard characters available somehow, and I am missing something really obvious?
N is at U+2115, R is at U+211D... just as described in the wikipedia article you linked to.  Odd that they aren't in the normal ABC order.  But, they are there.