How can I generate a series of repeating numbers in PostgreSQL?

Question

In PostgreSQL, is it possible to generate a series of repeating numbers? For example, I want to generate the numbers 1 to 10, with each number repeated 3 times:

Answer 1

SELECT * FROM (SELECT generate_series(1, 10)) A
JOIN (
  SELECT generate_series(1, 3)
) B ON (TRUE)

http://www.sqlfiddle.com/#!12/d41d8