Data commit

Task/Catalan-numbers/Perl/catalan-numbers-1.pl

@@ -0,0 +1,7 @@
+sub factorial { my $f = 1; $f *= $_ for 2 .. $_[0]; $f; }
+sub catalan {
+  my $n = shift;
+  factorial(2*$n) / factorial($n+1) / factorial($n);
+}
+
+print "$_\t@{[ catalan($_) ]}\n" for 0 .. 20;

Task/Catalan-numbers/Perl/catalan-numbers-2.pl

@@ -0,0 +1,8 @@
+my @c = (1);
+sub catalan {
+        use bigint;
+        $c[$_[0]] //= catalan($_[0]-1) * (4 * $_[0]-2) / ($_[0]+1)
+}
+
+# most of the time is spent displaying the long numbers, actually
+print "$_\t", catalan($_), "\n" for 0 .. 10000;

Task/Catalan-numbers/Perl/catalan-numbers-3.pl

@@ -0,0 +1,6 @@
+use ntheory qw/binomial/;
+sub catalan {
+  my $n = shift;
+  binomial(2*$n,$n)/($n+1);
+}
+print "$_\t", catalan($_), "\n" for 0 .. 10000;