OFFSET
1,2
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..5000
FORMULA
Multiplicative closure of A006562.
PROG
(Haskell)
import Data.Set (singleton, fromList, union, deleteFindMin)
a225494 n = a225494_list !! (n-1)
a225494_list = 1 : h (singleton p) ps [p] where
(p:ps) = a006562_list
h s xs'@(x:xs) ys
| m > x = h (s `union` (fromList $ map (* x) (1 : ys))) xs ys
| otherwise = m : h (s' `union` (fromList $ map (* m) ys')) xs' ys'
where ys' = m : ys; (m, s') = deleteFindMin s
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, May 09 2013
STATUS
approved