A007187 Leech's tree-labeling problem for n nodes.

1, 3, 6, 9, 15, 20, 26, 34, 41

Offset: 2

Author

N. J. A. Sloane

Keywords

• nonn
• hard
• nice
• more

Comments

a(11) >= 48, a(12) >= 55.

a(n) is the greatest number k such that there exists a tree with n nodes and integral edge labels such that for each integer 1 <= m <= k, there exists a pair of nodes such that the sum of the edge labels on the path connecting the two nodes equals m. - Charlie Neder, Apr 26 2019

References

• R. K. Guy, Unsolved Problems in Number Theory, Sect. C10.
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• R. K. Guy, A quarter century of "Monthly" unsolved problems, 1969-1993, Amer Math. Monthly, 100 (1993), 945-949.
• J. Leech, On the representation of 1, 2, ..., n by differences, J. Lond. Math. Soc. 31 (1956), 160-169.
• Index entries for sequences related to trees

Crossrefs

Cf. A005488.