OFFSET
1,2
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
MATHEMATICA
Select[Range[500], Complement[Union[IntegerDigits[#, 3]], Union[IntegerDigits[#, 7]]]=={}&] (* Harvey P. Dale, Jan 28 2024 *)
PROG
(Haskell)
import Data.List ((\\), nub)
a037383 n = a037383_list !! (n-1)
a037383_list = filter f [1..] where
f x = null $ nub (ds 3 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
(PARI) upto(N) = my(s7); [n|n<-[1..N], setunion(Set(digits(n, 3)), s7=Set(digits(n, 7)))==s7]; \\ Ruud H.G. van Tol, May 09 2024
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved