Answer that the I Ching calculator purchased by Dirk Gently in Douglas Adams' The Long Dark Teatime of the Soul gives for any math problem yielding a number greater than 4 (in addition to hexagrams and commentary on them). "Dirk was not certain if this was a programming error or an insight beyond his ability to fathom, but he was crazy about it anyway, enough to hand over £20 of ready cash for the thing."

Apparently at least one Javascript programmer has made a Web version of this calculator, now at http://www.thateden.co.uk/dirk/