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A037403 Numbers n such that every base 7 digit of n is a base 9 digit of n. 4
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. 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

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Last modified July 20 05:56 EDT 2019. Contains 325168 sequences. (Running on oeis4.)