OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..13
Omer Berkman, Baruch Schieber and Uzi Vishkin, Optimal doubly logarithmic parallel algorithms based on finding all nearest smaller values, Journal of Algorithms, 14(1993)(3): 344-370.
FORMULA
a(0)=0, a(1)=2; for n>1, a(n) = 2^(2^(n-2)).
MATHEMATICA
Join[{0, 2}, Table[2^2^(n-2), {n, 2, 9}]] (* Harvey P. Dale, Feb 01 2014 *)
PROG
(Python)
def doubly_log_tree_children(n):
if n==0:
return 0
if n==1:
return 2
return 2**(2**(n-2))
CROSSREFS
KEYWORD
nonn
AUTHOR
Chad Brewbaker, Dec 04 2009
EXTENSIONS
More terms from Harvey P. Dale, Feb 01 2014
STATUS
approved