login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A110752 a(n) is the number of divisors of the concatenation of 1089 with itself n times. 3

%I

%S 9,36,192,144,288,1536,576,4608,3840,4608,3072,12288,1152,9216,

%T 1572864,73728,2304,245760,144,73728,4718592,49152,2304,6291456,

%U 294912,18432,589824,294912,18432,100663296

%N a(n) is the number of divisors of the concatenation of 1089 with itself n times.

%C 1089 has the property that any number of concatenations of it with itself and its digit reversal have the same set of distinct prime factors.

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

%t k = 0; Do[k = 10^4 * k + 1089; Print[DivisorSigma[0, k]], {n, 1, 30}] (* _Ryan Propper_, Oct 15 2005 *)

%Y Cf. A110751, A110753.

%K base,nonn

%O 1,1

%A _Amarnath Murthy_, Aug 11 2005

%E a(19)-a(30) from _Ryan Propper_, Oct 15 2005

%E Name edited by _Jon E. Schoenfield_, Nov 19 2018

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 29 07:00 EDT 2021. Contains 346340 sequences. (Running on oeis4.)