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Re: Concatenation of prime factors of numbers

  • To: mathgroup at smc.vnet.net
  • Subject: [mg78637] Re: Concatenation of prime factors of numbers
  • From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
  • Date: Thu, 5 Jul 2007 05:59:13 -0400 (EDT)
  • Organization: The Open University, Milton Keynes, UK
  • References: <f6i940$1mj$1@smc.vnet.net>

Diana wrote:
> Can someone help me with this trick?
> 
> I would like to create the following sequence, based on FactorInteger:
> 
> 2,3,22,5,23,7,222,33,25,11,223,13,27,35,2222, ...
> 
> where each term is the concatenation of the prime factors of n.
> 
> Thanks,
> 
> Diana

Are you talking about Home Prime sequence [1, 2] ? The On-Line 
Encyclopedia of Integer Sequences [3] (among many others) returns

A037276 Replace n by concatenation of its prime factors in increasing 
order. [4]

What did you try with *FactorInteger*?

Regards,
Jean-Marc

[1] Weisstein, Eric W. "Home Prime." From MathWorld--A Wolfram Web 
Resource. http://mathworld.wolfram.com/HomePrime.html

[2] P. De Geest, "Home Primes", http://www.worldofnumbers.com/topic1.htm

[3] _The On-Line Encyclopedia of Integer Sequences_ 
http://www.research.att.com/~njas/sequences/Seis.html

[4] http://www.research.att.com/~njas/sequences/A037276


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