For larger n, you may get a faster solution by 
generating all partitions p of m for which 2<+./p .  
The actual perfect power would be  */p^p:i.#p



----- Original Message -----
From: Arie Groeneveld <[EMAIL PROTECTED]>
Date: Sunday, January 27, 2008 3:42
Subject: [Jprogramming] Perfect powers
To: Programming forum <[email protected]>

> JATK or let's say J4F.
> 
> Generating a sequence of ordered perfect powers <= N
> ref. OLEIS A001597
> 
> I have a tacit (pmt) and a explicit (pmx) version both with the same
> algorithm
> 
> *nb*   Without ext. prec.
> 
>    pmt 200
> 1 4 8 9 16 25 27 32 36 49 64 81 100 121 125 128 144 169 196
> 
>    10 ts 'pmt 2000000'
> 0.006247 232448
> 
>    10 ts 'pmx 2000000'
> 0.0036827 275712
> 
> 
>    x:{: pmx 2e6
> 1999396
> 
>    #pmt 1e6    NB. OLEIS A070428
> 1111
> 
> 
> Testing if a number > 1 is a perfect power:
> 
>    (1<[:+./[:{:__&q:) 220
> 0
> 
>    (1<[:+./[:{:__&q:) 32
> 1
> 
> 
> Just anxious to know (JATK) what's possible. :-)
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