my $x = 1/sqrt(5); for my $n (0 .. 28) { print int($x + 0.5), " "; $x *= (sqrt(5) + 1)/2; } print "\n";

##</code><code>##

my($x, $y) = (1, 0); for my $n (0 .. 28) { print $y, " "; ($x, $y) = ($y, $x + $y); } print "\n";

##</code><code>##

my $n = 28; $x = int(((1 + sqrt(5))/2)**$n / sqrt(5) + 0.5); print $x, "\n";

##</code><code>##

my $n = 28; my($a, $b, $c, $d, $x, $y) = (0, 1, 1, 1, 1, 0); { 0 != ($n & 1) and ($x, $y) = ($a*$x + $b*$y, $c*$x + $d*$y); $n <= 1 and last; $n >>= 1; ($a, $b, $c, $d) = ($a*$a + $b*$c, $a*$b + $b*$d, $c*$a + $d*$c, $c*$b + $d*$d); redo} print $y, "\n";

##</code><code>##

my $n = 28;
my($a, $b, $d, $x, $y) = (0, 1, 1, 1, 0);
{
        0 != ($n & 1) and ($x, $y) = ($a*$x + $b*$y, $b*$x + $d*$y);
        $n <= 1 and last;
        $n >>= 1;
        ($a, $b, $d) = ($a*$a + $b*$b, $a*$b + $b*$d, $b*$b + $d*$d);
redo}
print $y, "\n";

##</code><code>##

perl -le'$==1;1while print$==(1+$=+$=*sqrt 5)/2'
perl -le'$==1;1while print$==(1+sqrt 5)*$=/2+.5'
perl -le'$==1;1while print$==$=*1.6180339887+.5'
perl -le'for ($x = 1; $x = int(0.5 + $x * (sqrt(5) + 1)/2); ) { print $x; }'