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A110752
a(n) is the number of divisors of the concatenation of 1089 with itself n times.
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
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
Sequence in context: A265837 A264359 A280353 * A094973 A038780 A073984
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