Data update

Task/Mertens-function/PascalABC.NET/mertens-function.pas

@@ -0,0 +1,21 @@
+function mertens(max: integer): list<integer>;
+begin
+  result := (0..max).select( x -> 1).ToList;
+  foreach var n in 2..max do
+    foreach var k in 2..n do
+      result[n] -= result[n div k];
+end;
+
+begin
+  println('The first 99 Mertens numbers are:');
+  foreach var m in mertens(99) index i do
+    if i = 0 then write('   ')
+    else write(m:3, if i mod 10 = 9 then #10 else '');
+
+  var zeroes := mertens(1000).Where(x -> x = 0).Count;
+  println('M(N) equals zero', zeroes, 'times.');
+
+  var crosses := mertens(1000).Zip(mertens(1000).Skip(1), (x, y) -> (x <> 0) and (y = 0))
+                              .Where(x -> x).Count;
+  println('M(N) crosses zero', crosses, 'times.');
+end.