Thanks for the answers, seems like Mark-101232 had the shortest one.
SELECT col FROM (VALUES (1), (2), (3)) x(col)
@Jeff Moden - Not really, they just happens to be sequential, we use a fixed number of periods (3), that are not in the DB. I needed to join those with another table to get a desired result.
Your interest in sequential numbers, were you thinking of a tally table?