Number of distinct values taken by 2^2^...^2 (with n 2's and parentheses inserted in all possible ways).
1, 1, 1, 2, 4, 8, 17, 36, 78, 171, 379, 851, 1928, 4396, 10087, 23273, 53948, 125608
2 seqfan posts
Tue May 4 02:29:59 CEST 2010 [seqfan] Re: A177045: ordering of expressions built from numbers 2 and exponentiations