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A083897
Number of divisors of n with largest digit <= 2 (base 10).
3
1, 2, 1, 2, 1, 2, 1, 2, 1, 3, 2, 3, 1, 2, 1, 2, 1, 2, 1, 4, 2, 4, 1, 3, 1, 2, 1, 2, 1, 3, 1, 2, 2, 2, 1, 3, 1, 2, 1, 4, 1, 3, 1, 4, 1, 2, 1, 3, 1, 3, 1, 2, 1, 2, 2, 2, 1, 2, 1, 5, 1, 2, 2, 2, 1, 4, 1, 2, 1, 3, 1, 3, 1, 2, 1, 2, 2, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 3, 1, 2, 1, 2, 1, 3, 1, 2, 2, 5, 2, 3, 1, 2, 2
OFFSET
1,2
FORMULA
a(n) = A083888(n) + A083889(n) = A083898(n) - A083890(n).
Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = Sum_{k>=1} 1/A007089(k) = 2.09476944442950059256... . - Amiram Eldar, Jan 04 2024
MATHEMATICA
Table[Count[Divisors[n], _?(Max[IntegerDigits[#]]<3&)], {n, 110}] (* Harvey P. Dale, May 24 2019 *)
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, May 08 2003
STATUS
approved