diff -r 5322e1c46890 -r fb8ee3f58d19 progs/collatz2.scala
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/collatz2.scala	Sun Aug 21 00:39:04 2016 +0100
@@ -0,0 +1,5 @@
+def collatz(n: BigInt) : Boolean = n match {
+  case n if (n == 1) => true
+  case n if (n % 2 == 0) => collatz(n / 2)  
+  case _ => collatz(3 * n + 1)
+}