OFFSET
1,4
COMMENTS
The sum of the reciprocals of each row (n > 0) is 1 (i.e., 1/1, 1/2 + 1/2, 1/3 + 1/6 + 1/6 + 1/3, 1/4 + ... + 1/4, 1/5 + ... + 1/5, ...). The cut-the-knot link gives credit to Pierre Lamothe for this observation.
LINKS
Ivan Neretin, Table of n, a(n) for n = 1..4097
Alexander Bogomolny, Cut-the-knot on Stern-Brocot trees
FORMULA
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Joshua Zucker, May 11 2006
STATUS
approved