A037402 Numbers k such that every base-7 digit of k is a base-8 digit of k.

1, 2, 3, 4, 5, 6, 8, 16, 24, 32, 40, 48, 57, 85, 94, 106, 114, 133, 142, 163, 171, 196, 204, 212, 220, 224, 225, 226, 227, 228, 229, 230, 236, 244, 277, 285, 305, 334, 342, 385, 392, 401, 540, 546, 547, 550, 597, 620, 629, 646, 688

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base

Links

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

Crossrefs

Cf. A007093, A007094.

Cf. A037403, A037404.

Programs

Haskell

import Data.List ((\\), nub)
a037402 n = a037402_list !! (n-1)
a037402_list = filter f [1..] where
   f x = null $ nub (ds 7 x) \\ nub (ds 8 x)
   ds b x = if x > 0 then d : ds b x' else []  where (x', d) = divMod x b
-- Reinhard Zumkeller, May 30 2013

Mathematica

b7b8Q[n_]:=Module[{idn7=Union[IntegerDigits[n,7]]},Intersection[ idn7, Union[ IntegerDigits[n,8]]]==idn7]; Select[Range[700],b7b8Q] (* Harvey P. Dale, Dec 15 2013 *)