In 1984, British engineer Lee Sallows built a dedicated computer to compose a self-enumerating pangram — a sentence that inventories its own letters. It succeeded:

This pangram contains four a’s, one b, two c’s, one d, thirty e’s, six f’s, five g’s, seven h’s, eleven i’s, one j, one k, two l’s, two m’s, eighteen n’s, fifteen o’s, two p’s, one q, five r’s, twenty-seven s’s, eighteen t’s, two u’s, seven v’s, eight w’s, two x’s, three y’s, & one z.