OFFSET
1,2
COMMENTS
A sequence of distinct positive integers in which the ratios of successive terms (larger over smaller) are all distinct.
A100707 is an analogous sequence using addition and subtraction.
EXAMPLE
a(1)=1: 1 * 2 = 2 (k=2 is the smallest number not yet used as a divisor or multiplier).
a(2)=2: 2 * 3 = 6 (k=3 has not been used before).
a(3)=6: 6 * 4 = 24 (k=4 has not been used before).
a(4)=24: 24 / 6 = 4 (k=6 has not been used before).
a(11)=72: 72 / 24 = 3 (k=24 has not been used before). Note that we would have used k=12 if this did not result in a repeated term (72 / 12 = a(3)=6).
CROSSREFS
KEYWORD
nonn
AUTHOR
Neal Gersh Tolunsky, Mar 19 2024
EXTENSIONS
a(12) and beyond from John Tyler Rascoe, Mar 20 2024
STATUS
approved