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

 

Logo

The OEIS Foundation is grateful to everyone who made a donation during our Annual Appeal.     Visit the new and spectacular Pictures from the OEIS page!

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A110752 a(n) = Tau(N), where N = the number obtained as a concatenation of 1089 with itself n times. Tau(n) = number of divisors of n. 3
9, 36, 192, 144, 288, 1536, 576, 4608, 3840, 4608, 3072, 12288, 1152, 9216, 1572864, 73728, 2304, 245760, 144, 73728, 4718592, 49152, 2304, 6291456, 294912, 18432, 589824, 294912, 18432, 100663296 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

1089 has the property that any number of concatenation of it with self and the digit reversal have same prime divisors.

LINKS

Table of n, a(n) for n=1..30.

EXAMPLE

a(2) =tau(10891089) = 36.

MATHEMATICA

k = 0; Do[k = 10^4 * k + 1089; Print[DivisorSigma[0, k]], {n, 1, 30}] (Propper)

CROSSREFS

Cf. A110751, A110753.

Sequence in context: A245416 A265837 A264359 * A094973 A038780 A073984

Adjacent sequences:  A110749 A110750 A110751 * A110753 A110754 A110755

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Aug 11 2005

EXTENSIONS

More terms from Ryan Propper, Oct 15 2005

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy .

Last modified February 6 01:00 EST 2016. Contains 268029 sequences.