OFFSET
1,2
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
FORMULA
Sum_{n>=1} 1/a(n) = (8*11)/((8-1)*(11-1)) = 44/35. - Amiram Eldar, Oct 07 2020
a(n) ~ exp(sqrt(2*log(8)*log(11)*n)) / sqrt(88). - Vaclav Kotesovec, Oct 07 2020
MATHEMATICA
Take[Union[8^First[#]*11^Last[#]&/@Tuples[Range[0, 20], 2]], 40] (* Harvey P. Dale, Jan 17 2015 *)
n = 10^6; Flatten[Table[8^i*11^j, {i, 0, Log[8, n]}, {j, 0, Log[11, n/8^i]}]] // Sort (* Amiram Eldar, Oct 07 2020 *)
PROG
(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a107788 n = a107788_list !! (n-1)
a107788_list = f $ singleton (1, 0, 0) where
f s = y : f (insert (8 * y, i + 1, j) $ insert (11 * y, i, j + 1) s')
where ((y, i, j), s') = deleteFindMin s
-- Reinhard Zumkeller, May 15 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Douglas Winston (douglas.winston(AT)srupc.com), Jun 14 2005
STATUS
approved