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A108779 revision #5

A108779
Numbers of the form (10^i)*(11^j), with i, j >= 0.
9
1, 10, 11, 100, 110, 121, 1000, 1100, 1210, 1331, 10000, 11000, 12100, 13310, 14641, 100000, 110000, 121000, 133100, 146410, 161051, 1000000, 1100000, 1210000, 1331000, 1464100, 1610510, 1771561, 10000000, 11000000, 12100000, 13310000
OFFSET
1,2
LINKS
PROG
(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a108779 n = a108779_list !! (n-1)
a108779_list = f $ singleton (1, 0, 0) where
f s = y : f (insert (10 * y, i + 1, j) $ insert (11 * y, i, j + 1) s')
where ((y, i, j), s') = deleteFindMin s
-- Reinhard Zumkeller, May 15 2015
KEYWORD
nonn
AUTHOR
Douglas Winston (douglas.winston(AT)srupc.com), Jun 26 2005
STATUS
approved