Answer:
467 Pokemon
Explanation:
There are 890 Pokemon, this number is counting the new generation, I mean 8 generation, in this case, we have 467 Pokemon only with one type.
There are not any website with this data, I had to create an Excel sheet, then I add different lists, I found the 890 different Pokemon with the first type and the second, the last step was to make a filter, with the type 2, where only show me Pokemon with the type 2 = blank.
