diff --git a/ardumont/schedule_csv_range.py b/ardumont/schedule_csv_range.py
index 48dff70..0823cb1 100644
--- a/ardumont/schedule_csv_range.py
+++ b/ardumont/schedule_csv_range.py
@@ -1,27 +1,46 @@
+#!/usr/bin/env python3
+
+# Copyright (C) 2018  The Software Heritage developers
+# See the AUTHORS file at the top-level directory of this distribution
+# License: GNU General Public License version 3, or any later version
+# See top-level LICENSE file for more information
+
+
 import click
+from math import floor
 
 
 @click.command()
-@click.option('--task-type', '-t', default='indexer_mimetype_range',
+@click.option('--task-type', '-t', default='indexer_range_mimetype',
               help='Add task type')
 @click.option('--policy', '-p', default='oneshot',
               help='Task policy, either oneshot or recurring')
-def main(task_type, policy):
-    # sha1 range
-    # 160 bits (20 byte) length
-    bound_max_minus = 2**159
-    bound_max = 2**160 - 1
-    step = 2**16
+@click.option('--number', '-n', default=10,
+              help='Number of ranges to compute')
+def main(task_type, policy, number):
+    """Compute ranges of sha1 (160 bits/20 bytes length)
+
+    """
+    # bits_number = 10
+    bits_number = 160
+    bound_max = 2**bits_number - 1
+    step = floor(bound_max / number)
+    bound_max_minus = bound_max - step
 
     def to_hex(number):
         return '{:040x}'.format(number)
 
     for start, end in zip(
             range(0, bound_max_minus, step), range(step, bound_max, step)):
         hex_start = to_hex(start)
         hex_end = to_hex(end)
-        print('%s;%s,["%s", "%s"]' % (task_type, policy, hex_start, hex_end))
+        print('%s;%s;["%s", "%s"]' % (task_type, policy, hex_start, hex_end))
+
+    if end < bound_max:
+        hex_start = to_hex(end)
+        hex_end = to_hex(bound_max)
+        print('%s;%s;["%s", "%s"]' % (task_type, policy, hex_start, hex_end))
 
 
 if __name__ == '__main__':
     main()