Is a divorce pronouncement counted if I uttered the words of divorce, "Go, you are divorced," intending my wife, while I was alone and under the impression that divorce does not occur in this manner?

The utterance of divorce by a sane person, not under duress, effects the divorce, whether he intended it or not. The presence of the wife or anyone else is not a condition. So, if he utters it by himself, the divorce takes effect, and he may take his wife back during her 'iddah (waiting period).