A037404 Numbers k such that every base-7 digit of k is a base-10 digit of k.

1, 2, 3, 4, 5, 6, 23, 46, 214, 250, 265, 285, 316, 421, 702, 1030, 1032, 1036, 1037, 1039, 1053, 1234, 1243, 1336, 1366, 1368, 1400, 1401, 1402, 1403, 1404, 1405, 1406, 1429, 1431, 1432, 1443, 1450, 1453, 1454, 1457, 1464

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A037402, A037403.

Programs

Haskell

import Data.List ((\\), nub)
a037404 n = a037404_list !! (n-1)
a037404_list = filter f [1..] where
   f x = null $ nub (ds 7 x) \\ nub (ds 10 x)
   ds b x = if x > 0 then d : ds b x' else []  where (x', d) = divMod x b
-- Reinhard Zumkeller, May 30 2013