A110752 a(n) is the number of divisors of the concatenation of 1089 with itself n times.

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

Offset

1,1

Comments

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.

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}] (* Ryan Propper, Oct 15 2005 *)

Crossrefs

Cf. A110751, A110753.

Sequence in context: A265837 A264359 A280353 * A094973 A038780 A073984

Adjacent sequences: A110749 A110750 A110751 * A110753 A110754 A110755

Keyword

base,nonn

Author

Amarnath Murthy, Aug 11 2005

Extensions

a(19)-a(30) from Ryan Propper, Oct 15 2005

Name edited by Jon E. Schoenfield, Nov 19 2018

Status

approved