There is more than one way to do it.

You can compute calculate the numbers from a simple sequence: 

my @f;
for my $i (0 .. 20) {
    my @e = (2 * $i, 2 * $i + 1);
    push @f, \@e;
}
print map "(@$_)", @f

[download]
or you can use the C-style loop to skip over the unwanted numbers: 
for (my $i = 0; $i <= 40; $i += 2) {
    my @e = ($i, $i + 1);
    push @f, \@e;
}

[download]
or you can use grep to filter the numbers you want: 
for my $i (grep 0 == $_ % 2, 0 .. 40) {
    my @e = ($i, $i + 1);
    push @f, \@e;
}

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etc.

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

In reply to Re^3: How Perl can push array into array and then how retrieve by choroba
in thread How Perl can push array into array and then how retrieve by Anonymous Monk

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