Initial data commit

Task/Multifactorial/D/multifactorial.d

@@ -0,0 +1,12 @@
+import std.stdio, std.algorithm, std.range;
+
+T multifactorial(T=long)(in int n, in int m) pure /*nothrow*/ {
+    T one = 1;
+    return reduce!q{a * b}(one, iota(n, 0, -m));
+}
+
+void main() {
+    foreach (immutable m; 1 .. 11)
+        writefln("%2d: %s", m, iota(1, 11)
+                               .map!(n => multifactorial(n, m)));
+}