Challenge 1: "Write a script to generate Van Eck's sequence
starting with 0.  Van Eck's sequence is defined by:

Let a0 = 0. Then, for n >= 0, if there exists an m < n such that am =
an, take the largest such m and set an+1 = n - m; otherwise an+1 = 0.

Thus the first occurrence of an integer in the sequence is followed by
a 0, and the second and subsequent occurrences are followed by the size
of the gap between the two most recent occurrences.

The sequence is named after Jan Ritsema van Eck, who submitted it to
the On-Line Encyclopedia of Integer Sequences.

The first few terms of the sequence are(OEIS: A181391):

    0, 0, 1, 0, 2, 0, 2, 2, 1, 6, 0, 5, 0, 2, 6, 5, 4, 0, 5..
"

My notes:

Sounds easy enough (and not, in fact, obviously recursive).



Challenge 2: "Using only the official postal (2-letter) abbreviations
for the 50 U.S. states, write a script to find the longest English word
you can spell? Here is the list of U.S. states abbreviations as per
wikipedia page. This challenge was proposed by team member Neil Bowers.

For example,
Pennsylvania + Connecticut = PACT
Wisconsin + North Dakota = WIND
Maine + Alabama = MEAL
California + Louisiana + Massachusetts + Rhode Island = Calamari
"

My notes:

Ok, looks like an interesting search problem.