Greatest and Least Prime Factors

[cino hilliard]

----Original Message Follows----
From: franktaw at netscape.net
To: seqfan at ext.jussieu.fr
Subject: Greatest and Least Prime Factors
Date: Tue, 29 Aug 2006 17:10:05 -0400

A quick survey shows that Lpf is used in the OEIS about equally often for 
the least prime factor and for the greatest (i.e., largest) prime factor.  
Gpf is often used instead for the greatest prime factor, and spf is 
sometimes used instead for the smallest prime factor.

What should the standard names be for these functions?  Is there a standard 
in the mathematical literature?

Do a google search.

My own vote would be for Lpf for least and Gpf for greatest.

My vote on this is to spell it out. Once someone here replied to a question 
I submitted and
used FLT. I thought he meant Fermat's Last Theorem but he meant Fermat's 
Little Theorem.
Big difference. It is certainly ok to use any combinations of letters to 
signify a sequence
as in A020639  Lpf(n): least prime dividing n (a(1)=1) as long as you define 
it. However, on this one, I do not see any difference using Lpd(n) here.

My eyes must be playing tricks. The first time I looked it up I would swear 
it read  Lpf(n): least
prime factor dividing n (a(1)=1).

Also Gpf is widely used as General Protection Fault in windows indicating a 
crash in your code.

Cino

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