A037385 - OEIS

%I #16 Aug 04 2021 02:21:28

%S 1,2,9,13,18,26,81,82,83,84,85,90,99,108,117,121,162,163,164,168,170,

%T 171,180,216,234,242,244,252,325,333,488,504,650,666,729,730,731,732,

%U 733,738,739,740,741,742,747,748,749,750,751

%N Numbers k such that every base-3 digit of k is a base-9 digit of k.

%H Reinhard Zumkeller, <a href="/A037385/b037385.txt">Table of n, a(n) for n = 1..10000</a>

%t Select[Range[1000],SubsetQ[IntegerDigits[#,9],IntegerDigits[#,3]]&] (* _Harvey P. Dale_, Dec 19 2015 *)

%o (Haskell)

%o import Data.List ((\\), nub)

%o a037385 n = a037385_list !! (n-1)

%o a037385_list = filter f [1..] where

%o    f x = null $ nub (ds 3 x) \\ nub (ds 9 x)

%o    ds b x = if x > 0 then d : ds b x' else []  where (x', d) = divMod x b

%o -- _Reinhard Zumkeller_, May 30 2013

%Y Cf. A007089, A007095.

%Y Cf. A037380, A037381, A037382, A037383, A037384, A037386.

%K nonn,base

%O 1,2

%A _Clark Kimberling_