Your h-index is the highest number n, such that you have at least n questions/answers, all of which have at least n score.
Q&A for professionals and students of engineering
select * from
(select top (1000) id from users order by reputation desc) z
cross apply ( select top(1) score from (select ds.score, postcount=(select count(*) from posts where owneruserid=z.id and score>=ds.score) from (select distinct score from posts where owneruserid=z.id) ds)scorecomp where postcount>=score
order by score desc) y