OFFSET
1,1
COMMENTS
Includes 2^k for all k > 4.
Conjecture: Let S be the set of all numbers whose prime signature is either {1,3}, {5}, or {1,1,2}. Then the sequence consists of all multiples of elements of S. - David A. Corneth, Jul 31 2018.
REFERENCES
R. P Stanley, Enumerative Combinatorics Vol. 1, Sec. 3.3.
LINKS
Wikipedia, Lattice (order)
EXAMPLE
In the poset of factorizations of 24, the factorizations (2*2*6) and (2*3*4) have two least-upper bounds, namely (2*12) and (4*6), so this poset is not a lattice.
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jul 30 2018
STATUS
approved