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%I #12 Jan 04 2024 03:24:36
%S 0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,1,0,1,0,0,0,0,0,
%T 0,1,0,1,1,0,0,0,0,0,1,0,0,0,1,0,0,0,0,1,0,0,1,1,1,0,0,0,1,0,0,0,0,0,
%U 1,0,0,1,0,0,0,1,0,1,1,0,1,0,0,0,0,0,1,0,1,2,1,1,1,1,2,1,1,2,2,0,0,0,0,0,0
%N Number of divisors of n with largest digit = 9 (base 10).
%C a(n) = A000005(n) - A083888(n) - A083889(n) - A083890(n) - A083891(n) - A083892(n) - A083893(n) - A083894(n) - A083895(n) = A000005(n) - A083903(n).
%H Robert Israel, <a href="/A083896/b083896.txt">Table of n, a(n) for n = 1..10000</a>
%e n=117, 2 of the 6 divisors of 117 have largest digit =9: {9,39}, therefore a(117)=2.
%p f:= proc(n) nops(select(t -> max(convert(t, base, 10))=d, numtheory:-divisors(n))) end proc:
%p d:= 9:
%p map(f, [$1..200]); # _Robert Israel_, Oct 06 2019
%t Table[Count[Divisors[n],_?(Max[IntegerDigits[#]]==9&)],{n,110}] (* _Harvey P. Dale_, Mar 15 2018 *)
%Y Cf. A054055, A000005, A083888, A083889, A083890, A083891, A083892, A083893, A083894, A083895.
%K nonn,base
%O 1,90
%A _Reinhard Zumkeller_, May 08 2003
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