5.3.1  Sequences: seq[] ()

A sequence is represented by a sequence of elements separated by commas, without delimiters or with either parentheses (( and )) or seq[ and ] as delimiters, as in:
Input:

or:

or:

Output:

Note that the order of the elements of a sequence is significant. For example, if B:=(5,6,3,4) and C:=(3,4,5,6), then B==C returns false.
(A value can be assigned to a variable with the := operator; see Section 5.4.1. Also, == is the test for equality; see Section 6.1.2.)

Note also that the expressions seq[…] and seq(…) are not the same (see Section 6.39.2 for information on seq(…)). For example, seq([0,2])=(0,0) and seq([0,1,1,5])=[0,0,0,0,0] but
seq[0,2]=(0,2) and seq[0,1,1,5]=(0,1,1,5)

See Section 6.39 for operations on sequences.