AWK to print every nth line from a file

Question

i want to print every Nth line of a file using AWK. i tried modifying the general format :-

awk \'0 == NR % 4\' results.txt

to:-

Answer 1

This do also work, but its not a good practice.

awk '!(NR%'$ct')' results.txt

This is ok to use:

awk '!(NR%n)' n="$ct" results.txt