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A037374
Positive numbers k such that every base-2 digit of k is a base-5 digit of k.
8
1, 5, 7, 25, 26, 27, 28, 29, 30, 31, 35, 40, 45, 51, 55, 76, 80, 101, 105, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155
OFFSET
1,2
LINKS
PROG
(Haskell)
import Data.List ((\\), nub)
a037374 n = a037374_list !! (n-1)
a037374_list = filter f [1..] where
f x = null $ nub (ds 2 x) \\ nub (ds 5 x)
ds b x = if x > 0 then d : ds b x' else [] where (x', d) = divMod x b
-- Reinhard Zumkeller, May 30 2013
KEYWORD
nonn,base
STATUS
approved