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A083899 Number of divisors of n with largest digit <= 4 (base 10). 4
1, 2, 2, 3, 1, 3, 1, 3, 2, 3, 2, 5, 2, 3, 2, 3, 1, 3, 1, 5, 3, 4, 2, 6, 1, 3, 2, 4, 1, 5, 2, 4, 4, 3, 1, 5, 1, 2, 3, 6, 2, 6, 2, 6, 2, 3, 1, 6, 1, 3, 2, 4, 1, 3, 2, 4, 2, 2, 1, 8, 1, 3, 3, 4, 2, 6, 1, 4, 3, 4, 1, 6, 1, 2, 2, 3, 2, 4, 1, 6, 2, 3, 1, 8, 1, 3, 2, 6, 1, 5, 2, 4, 3, 2, 1, 7, 1, 3, 4, 6, 2, 5, 2, 5, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
a(n) = A083898(n) + A083891(n) = A083900(n) - A083892(n).
Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = Sum_{k>=1} 1/A007091(k) = 3.92521682598923397031... . - Amiram Eldar, Jan 04 2024
MATHEMATICA
a[n_] := DivisorSum[n, 1 &, Max[IntegerDigits[#]] <= 4 &]; Array[a, 100] (* Amiram Eldar, Jan 04 2024 *)
CROSSREFS
Sequence in context: A180257 A265576 A083040 * A339461 A190263 A144911
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, May 08 2003
STATUS
approved

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Last modified March 28 22:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)