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Positive numbers n such that the set of base-7 digits of n equals both the set of base-8 digits of n and the set of base-9 digits of n.
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%I #16 Sep 12 2017 02:46:13

%S 1,2,3,4,5,6,32942,103302,142489,178248,263180,361369,362370,378454,

%T 540929,540940,567333,567337,590697,693302,723659,726195,743217,

%U 829792,888934,1070221,1073830,1074177,1083411,1083738,1090352,1106956,1129738,1139557,1139881,1201762,1249562

%N Positive numbers n such that the set of base-7 digits of n equals both the set of base-8 digits of n and the set of base-9 digits of n.

%H Robert Israel, <a href="/A292125/b292125.txt">Table of n, a(n) for n = 1..1000</a>

%e 32942 in base 7 is 165020; in base 8 is 100256; and in base 9 is 50162. The set of digits for all three is {0, 1, 2, 5, 6}.

%p filter:= proc(n) local S;

%p S:= convert(convert(n,base,9),set);

%p nops(S intersect {7,8})=0 and evalb(convert(convert(n,base,8),set)=S) and evalb(convert(convert(n,base,7),set)=S)

%p end proc:

%p select(filter, [$1..6,seq(seq(9*a+b,b=0..6),a=1..7*9^5-1)]); # _Robert Israel_, Sep 11 2017

%t Select[Range[5/4*10^6], Function[k, SameQ @@ Map[Union@ IntegerDigits[k, #] &, {7, 8, 9}]]] (* _Michael De Vlieger_, Sep 10 2017 *)

%o (PARI) isok(n) = my(s7 = Set(digits(n, 7)), s8 = Set(digits(n, 8)), s9 = Set(digits(n, 9))); (s7 == s8) && (s8 == s9); \\ _Michel Marcus_, Sep 09 2017

%Y Subsequence of A037438.

%K nonn,base

%O 1,2

%A _Paul Lusch_, Sep 08 2017

%E More terms from _Michel Marcus_, Sep 09 2017