Enumeration of permutations of {1, ..., n} with n = 15 by values of L_n, 
the length of the longest increasing subsequence.  There is 1 permutation 
with L_n = 1, 9694844 with L_n = 2, etc.

  1:1
  2:9694844
  3:8017098273
  4:164161815768
  5:485534447114
  6:434119587475
  7:172912977525
  8:37558353900
  9:4927007100
 10:410474625
 11:22128576
 12:766221
 13:16381
 14:196
 15:1