OFFSET
1,8
LINKS
Scott R. Shannon, Table of n, a(n) for n = 1..1000
FORMULA
EXAMPLE
a(9) = 5 as {1,2,...,9} contains the geometric progressions [1,2,4], [1,2,4,8], [2,4,8], [1,3,9], [4,6,9].
CROSSREFS
KEYWORD
nonn
AUTHOR
Scott R. Shannon and N. J. A. Sloane, Oct 23 2023
STATUS
approved