login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A083891 Number of divisors of n with largest digit = 4 (base 10). 11
0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 2, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 2, 1, 2, 1, 2, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 2, 0, 1, 0, 2, 0, 0, 0, 1, 0, 0, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 0, 0, 1, 0, 0, 0, 2, 0, 1, 0, 1, 0, 1, 0, 2, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,24

COMMENTS

a(n) = A000005(n) - A083888(n) - A083889(n) - A083890(n) - A083892(n) - A083893(n) - A083894(n) - A083895(n) - A083896(n) = A083899(n) - A083898(n).

LINKS

Table of n, a(n) for n=1..105.

EXAMPLE

n=120, 3 of the 16 divisors of 120 have largest digit =4:

{4,24,40}, therefore a(120)=3.

MATHEMATICA

Table[Count[Divisors[n], _?(Max[IntegerDigits[#]]==4&)], {n, 110}] (* Harvey P. Dale, Feb 19 2016 *)

CROSSREFS

Cf. A054055, A000005, A083899.

Sequence in context: A130207 A167688 A083914 * A087623 A265260 A269243

Adjacent sequences:  A083888 A083889 A083890 * A083892 A083893 A083894

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller, May 08 2003

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified February 24 12:50 EST 2018. Contains 299623 sequences. (Running on oeis4.)