A sequence of letters is considered "valid" if it occurs as a substring of a common English word. For example, "RGRO" is valid because it occurs in the word "undeRGROund."

Find a sequence of four distinct letters such that all 23 non-identity permutations of the sequence are valid.

(In reply to Another one (weird but not dreigh) by Penny)

This is a very interesting attempt, and some of these words are, well, not too common but still it's great.  Yet you missed one combination: the very first combination you mentioned, EIDR.  Please tell me which word includes EIDR in that order.

Posted by Alexis on 2005-11-02 19:18:09