A037403 - OEIS

A037403

Numbers k such that every base-7 digit of k is a base-9 digit of k.

1, 2, 3, 4, 5, 6, 31, 99, 106, 107, 195, 198, 248, 257, 284, 297, 321, 498, 514, 749, 750, 751, 758, 767, 785, 936, 939, 940, 943, 950, 968, 996, 1028, 1086, 1088, 1110, 1163, 1200, 1218, 1254, 1453, 1471, 1498, 1500, 1502, 1507

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

PROG

(Haskell)

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

a037403 n = a037403_list !! (n-1)

a037403_list = filter f [1..] where

f x = null $ nub (ds 7 x) \\ nub (ds 9 x)

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

-- Reinhard Zumkeller, May 30 2013

CROSSREFS

Cf. A007093, A007095.

Cf. A037402, A037404.

Sequence in context: A037332 A091690 A024640 * A037439 A004846 A178579

Adjacent sequences: A037400 A037401 A037402 * A037404 A037405 A037406

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved