OFFSET

1,3

COMMENTS

Length of shortest ruler with n marks, with no mark halfway between two other marks. - Christian Häggström, Nov 19 2018

REFERENCES

R. K. Guy, Unsolved Problems in Number Theory, E10 (but beware of errors).

LINKS

Noam Benson-Tilsen, Samuel Brock, Brandon Faunce, Monish Kumar, Noah Dokko Stein, and Joshua Zelinsky, Total Difference Labeling of Regular Infinite Graphs, arXiv:2107.11706 [math.CO], 2021.

B. E. Brown and D. M. Gordon, On sequences without geometric progressions, Math. Comp. 65 (1996), no. 216, 1749-1754.

FORMULA

a(n) = A065825(n) - 1.

EXAMPLE

Example for a(10) = 23: 0 1 4 6 10 15 17 18 22 23.

CROSSREFS

KEYWORD

nonn,more

AUTHOR

EXTENSIONS

a(1)-a(2) prepended and a(42)-a(43) derived from A065825 by Alois P. Heinz, Nov 18 2018

STATUS

approved