Semiprime's dividers concatenated

[alexandre.wajnberg at skynet.be]

Hi Eric and Bob,

Just one remarquable pattern below (among others a presume):
reading the next six n-th four-digit terms, they finish allways by the 
two digits [11 13 17 19 23 29], this cycle repeating... while the two 
first digits
of theese next six n-th four-digit terms  are 11^6 [= 11 11 11 11 11 
11], then 13^6, 17^6, 19^6, 23^6, 29^6!

Alexandre
---------
Le lundi, 9 mai 2005, à 16:56 Europe/Brussels, Robert G. Wilson v a 
écrit :

> Dear Eric,
>
> 	Easy, just build it from the concatenation of the primes.
>
> Sort[ Flatten[ Table[ FromDigits[ Join[ IntegerDigits[ Prime[i]], 
> IntegerDigits[ Prime[j]] ]], {i, 10}, {j, 10}] ]]
>
> 22, 23, 25, 27, 32, 33, 35, 37, 52, 53, 55, 57, 72, 73, 75, 77, 112, 
> 113, 115, 117, 132, 133, 135, 137, 172, 173, 175, 177, 192, 193, 195, 
> 197, 211, 213, 217, 219, 223, 229, 232, 233, 235, 237, 292, 293, 295, 
> 297, 311, 313, 317, 319, 323, 329, 511, 513, 517, 519, 523, 529, 711, 
> 713, 717, 719, 723, 729, 1111, 1113, 1117, 1119, 1123, 1129, 1311, 
> 1313, 1317, 1319, 1323, 1329, 1711, 1713, 1717, 1719, 1723, 1729, 
> 1911, 1913, 1917, 1919, 1923, 1929, 2311, 2313, 2317, 2319, 2323, 
> 2329, 2911, 2913, 2917, 2919, 2923, 2929
>
> Sincerely, Bob.
>
>
> Eric Angelini wrote:
>
>> Hello SeqFan,
>> Here are the first semiprimes (A001358):
>> 4,6,9,10,14,15,21,22,25,26,33,34,35,38,39,46...
>> I've just submitted to the OEIS quite a lot of
>> sequences dealing with the concatenation of the
>> dividers of the semiprimes, e.g.:
>> First semiprime is 4; 4 is 2x2 --> 22
>> Second semiprime is 6; 6 is 3x2 --> 32
>>                          or 2x3 --> 23
>> Third semiprime is 9; 9 is 3x3 --> 33
>> Fourth semiprime is 10; 10 is 2x5 --> 25
>>                            or 5x2 --> 52
>> etc.
>> How would look an increasing sequence with
>> all such "concatenated dividers", starting
>> with the smallest one? I'm unable to build
>> it by hand, fearing as always to forget one
>> result behind...
>> Best,
>> É.
>