Bash define vector with a variable

Question

i couldn't find an answer in internet for this:

$ echo {1..20}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

But if I try to use a variable to define the limit:

$ x=20
$ echo {1..$x}
{1..$x}

Anyone knows how make it work? Thanks in advance.

Answer 1

$ x=20
$ eval echo {1..$x}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20