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

Author

Amarnath Murthy, Aug 11 2005

Keywords

• base
• nonn

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.

Examples

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

Crossrefs

Cf. A110751, A110753.

Programs

Mathematica

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

Extensions

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

Name edited by Jon E. Schoenfield, Nov 19 2018