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A045811 In the list of divisors of n (in base 3), each digit 0-2 appears equally often.

%I A045811 #15 Nov 15 2020 08:21:09
%S A045811 20,10022,10202,12002,12020,12200,20012,20102,20120,20201,20210,20220,
%T A045811 21002,21200,22002,22010,22020,22100,22200,1210020,1210022,1212200,
%U A045811 1220100,10222011,12200220,12202020,12210210,20010121,20010212
%N A045811 In the list of divisors of n (in base 3), each digit 0-2 appears equally often.
%H A045811 Robert Israel, <a href="/A045811/b045811.txt">Table of n, a(n) for n = 1..2500</a>
%H A045811 Naohiro Nomoto, <a href="http://www.geocities.co.jp/Technopolis/1793/09digit.htm">In the list of divisors of n,... </a> [Broken link]
%e A045811 Divisors of 12200 are (1, 10, 100, 122, 1220, 12200); the numbers of digits (0-2) are [0(6), 1(6), 2(6)].
%p A045811 f:= proc(n) local D,v,r,i;
%p A045811   D:= map(op@convert,convert(numtheory:-divisors(n),list),base,3);
%p A045811   if nops({numboccur(0,D),numboccur(1,D),numboccur(2,D)})=1 then
%p A045811     r:= convert(n,base,3);
%p A045811     add(r[i]*10^(i-1),i=1..nops(r))
%p A045811   fi
%p A045811 end proc:
%p A045811 map(f, [$1..3^8]); # _Robert Israel_, Nov 14 2020
%Y A045811 Cf. A038564, A038565, A045812.
%K A045811 nonn,base
%O A045811 1,1
%A A045811 _Naohiro Nomoto_