1
11
121
1331
14641
.......

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;

my $i;
my $j;
my $k;
my @a;
my @b;

$a[0] = 1;
$a[1] = 1;

for($i=0;$i<=10;$i++){
        @a = &yh(@a);
        print @a,"\n";
}


sub yh{
        my(@a)=@_;
        my @b;
        my $j;
        my $k;

        $k = $#a + 1;

        $b[0] = 1;


        for($i=1;$i<=$k;$i++){
                $j = $i - 1;
                $b[$i] = $a[$i] + $a[$j];
        }
        $b[$k] = 1;
        return @b;
}


##</code><code>##

phillip@Athen:~/script$ perl yanghui.pl
Use of uninitialized value in addition (+) at yanghui.pl line 34.
121
Use of uninitialized value in addition (+) at yanghui.pl line 34.
1331
Use of uninitialized value in addition (+) at yanghui.pl line 34.
14641
Use of uninitialized value in addition (+) at yanghui.pl line 34.
15101051
Use of uninitialized value in addition (+) at yanghui.pl line 34.
1615201561
Use of uninitialized value in addition (+) at yanghui.pl line 34.
172135352171
Use of uninitialized value in addition (+) at yanghui.pl line 34.
18285670562881
Use of uninitialized value in addition (+) at yanghui.pl line 34.
193684126126843691