Subscribe!


It is now possible to subscribe to the site, which will get you:
  • one extra "special puzzle" every day, which can be solved any time:
    • Sunday: 6x6 "no-op"
    • Monday: 7x7 twin
    • Tuesday: 8x8 with exponentiation
    • Wednesday: 10x10 (medium)
    • Thursday: 7x7 with negative numbers
    • Friday: 8x8 twin
    • Saturday: 15x15 or 7x7 "no-op" twin from zero
    Each extra puzzle is worth 8 points
  • up to 4 puzzles against the clock of each size (instead of 2)
  • all ads permanently disabled
  • more bonus puzzles
  • the ability to do puzzles of up to 1 month ago (instead of 1 week)
    (so you can still score points for extra puzzles of up 1 month old)

The one year subscription will also get you three free books (as PDF downloads)
(note: these are new books, and not for sale separately):

  • "201 Tricky Calcudoku Puzzles, Extra".
    The 41 difficult puzzles in this book are worth 5 points each.

  • "102 Large Calcudoku Puzzles, Extra".
    The 32 difficult puzzles in this book are worth 10 points each.

  • "The Ten 10 Years of www.calcudoku.org 10x10 Puzzles"
    The 10 puzzles in this book are worth 10 points each.

 New: when you renew your annual subscription, you'll get the book "51 Advanced Puzzles" (also as a PDF download, and also not for sale separately). When you renew a 2nd time, you'll get volume II of this book (with, for example, "no-op" puzzles, ten 10x10 twin puzzels, and one 17x17 puzzle):

The six month subscription will get you one free book (of the first two, specify which one you prefer when ordering).

Subscriptions are not automatically renewed (you can add a new subscription at any time).

Payment is done through Paypal (where you can pay using a Paypal account or credit card; so note that no payment information is stored on this site).

Note: after payment, wait until you return to the site, then your subscription will be started automatically.

One month subscription, all benefits except the free books
$2.49
Note: You have to be logged in before you can subscribe.

Six month subscription, all benefits and one free book
$11.95
Note: You have to be logged in before you can subscribe.

One year subscription, all benefits and two free books
$19.95
Note: You have to be logged in before you can subscribe.

Change currency:    € Euro  |  £ British pound  |  $ US dollar  |  ¥ Japanese Yen

It is also possible to become a subscriber by bank transfer to IBAN NL06 KNAB 0404 5101 67 to "Patrick Min Computer Programming", the Netherlands. Don't forget to put your username (!) in the transfer comments, and (for the 6 month subscription) the book you'd like.

Donate

You can also support the site by giving a donation. This will be much appreciated, but is of course not required.