A037383 Numbers k such that every base-3 digit of k is a base-7 digit of k.

1, 2, 13, 51, 63, 67, 68, 79, 84, 91, 99, 105, 134, 205, 211, 246, 252, 345, 351, 352, 354, 355, 357, 358, 359, 360, 361, 362, 363, 364, 366, 373, 380, 387, 394, 401, 406, 441, 442, 443, 444, 445, 446, 447, 448, 449, 454, 455, 457

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

Cf. A007089, A007093.

Cf. A037380, A037381, A037382, A037384, A037385, A037386.

Sequence in context: A056305 A056297 A241892 * A034476 A030517 A048502

Adjacent sequences: A037380 A037381 A037382 * A037384 A037385 A037386

Keyword

nonn,base

Author

Clark Kimberling

Status

approved