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Number of divisors of n with largest digit <= 5 (base 10).
4

%I #9 Jan 04 2024 01:48:49

%S 1,2,2,3,2,3,1,3,2,4,2,5,2,3,4,3,1,3,1,6,3,4,2,6,3,3,2,4,1,7,2,4,4,3,

%T 3,5,1,2,3,7,2,6,2,6,5,3,1,6,1,6,3,5,2,4,4,4,2,2,1,10,1,3,3,4,3,6,1,4,

%U 3,6,1,6,1,2,5,3,2,4,1,7,2,3,1,8,2,3,2,6,1,8,2,4,3,2,2,7,1,3,4,9,2,6,2,6,7

%N Number of divisors of n with largest digit <= 5 (base 10).

%F a(n) = A083899(n) + A083892(n) = A083901(n) - A083893(n).

%F Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = Sum_{k>=1} 1/A007092(k) = 5.25448032967060504709... . - _Amiram Eldar_, Jan 04 2024

%t Table[Count[Divisors[n],_?(Max[IntegerDigits[#]]<6&)],{n,110}] (* _Harvey P. Dale_, Feb 02 2015 *)

%Y Cf. A054055, A000005, A007092, A083892, A083893, A083899, A083901.

%K nonn,base

%O 1,2

%A _Reinhard Zumkeller_, May 08 2003