cp's OEIS Frontend

A037394 Numbers k such that every base-5 digit of k is a base-7 digit of k.

%I A037394 #17 Aug 05 2021 07:00:08
%S A037394 1,2,3,4,17,51,66,102,109,123,156,158,162,206,218,312,317,324,361,381,
%T A037394 416,418,423,458,462,463,466,467,468,472,494,518,545,546,549,556,557,
%U A037394 559,562,584,606,619,621,630,640,651,658,687
%N A037394 Numbers k such that every base-5 digit of k is a base-7 digit of k.
%H A037394 Reinhard Zumkeller, <a href="/A037394/b037394.txt">Table of n, a(n) for n = 1..10000</a>
%t A037394 Select[Range[700],SubsetQ[IntegerDigits[#,7],IntegerDigits[#,5]]&] (* _Harvey P. Dale_, Sep 29 2017 *)
%o A037394 (Haskell)
%o A037394 import Data.List ((\\), nub)
%o A037394 a037394 n = a037394_list !! (n-1)
%o A037394 a037394_list = filter f [1..] where
%o A037394    f x = null $ nub (ds 5 x) \\ nub (ds 7 x)
%o A037394    ds b x = if x > 0 then d : ds b x' else []  where (x', d) = divMod x b
%o A037394 -- _Reinhard Zumkeller_, May 30 2013
%Y A037394 Cf. A007091, A007093.
%Y A037394 Cf. A037393, A037395, A037396, A037397.
%K A037394 nonn,base
%O A037394 1,2
%A A037394 _Clark Kimberling_