--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/testing1/collatz.scala	Tue Nov 14 13:14:47 2017 +0000
@@ -0,0 +1,20 @@
+// Part 1 about the 3n+1 conjecture
+//==================================
+
+object CW6a {
+
+def collatz(n: Long): Long =
+  if (n == 1) 1 else
+    if (n % 2 == 0) 1 + collatz(n / 2) else 
+      1 + collatz(3 * n + 1)
+
+
+def collatz_max(bnd: Long): (Long, Long) = {
+  val all = for (i <- (1 to bnd.toInt).toList) yield collatz(i)
+  val max = all.max
+  (max, all.indexOf(max) + 1)
+}
+
+
+}
+