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.
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
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