A037376 Positive numbers k such that every base-2 digit of k is a base-7 digit of k.

1, 7, 15, 49, 50, 51, 52, 53, 54, 55, 56, 63, 70, 77, 84, 91, 99, 105, 127, 148, 154, 197, 203, 246, 252, 255, 295, 301, 343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 359, 360, 361, 362, 363, 364

Offset

1,2

Links

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

Mathematica

mtchQ[n_]:=Module[{b7=Union[IntegerDigits[n, 7]], b2=Union[IntegerDigits[n, 2]]}, MemberQ[Partition[b7, Length[b2], 1], b2]]
Select[Range[400], mtchQ]  (* Harvey P. Dale, Feb 20 2011 *)

Prog

(Haskell)
import Data.List ((\\), nub)
a037376 n = a037376_list !! (n-1)
a037376_list = filter f [1..] where
   f x = null $ nub (ds 2 x) \\ nub (ds 7 x)
   ds b x = if x > 0 then d : ds b x' else []  where (x', d) = divMod x b
-- Reinhard Zumkeller, May 30 2013

Crossrefs

Cf. A037372, A037373, A037374, A037375, A037377, A037378, A037379.

Sequence in context: A309732 A309493 A145978 * A141548 A146159 A187986

Adjacent sequences: A037373 A037374 A037375 * A037377 A037378 A037379

Keyword

nonn,base

Author

Clark Kimberling

Status

approved