cp's OEIS Frontend

A037391 Numbers k such that every base-4 digit of k is a base-9 digit of k.

%I A037391 #15 Jul 12 2024 18:33:21
%S A037391 1,2,3,81,84,85,93,101,102,105,106,110,162,168,170,174,190,191,243,
%T A037391 244,252,253,254,255,325,341,650,750,758,768,837,885,894,918,919,921,
%U A037391 922,923,925,926,939,957,972,973,974,975,976,977
%N A037391 Numbers k such that every base-4 digit of k is a base-9 digit of k.
%H A037391 Reinhard Zumkeller, <a href="/A037391/b037391.txt">Table of n, a(n) for n = 1..10000</a>
%t A037391 Select[Range[1000],SubsetQ[IntegerDigits[#,9],IntegerDigits[#,4]]&] (* _Harvey P. Dale_, Jul 12 2024 *)
%o A037391 (Haskell)
%o A037391 import Data.List ((\\), nub)
%o A037391 a037391 n = a037391_list !! (n-1)
%o A037391 a037391_list = filter f [1..] where
%o A037391    f x = null $ nub (ds 4 x) \\ nub (ds 9 x)
%o A037391    ds b x = if x > 0 then d : ds b x' else []  where (x', d) = divMod x b
%o A037391 -- _Reinhard Zumkeller_, May 30 2013
%Y A037391 Cf. A037387, A037388, A037389, A037390, A037392.
%K A037391 nonn,base
%O A037391 1,2
%A A037391 _Clark Kimberling_