Math::NumSeq::AllPrimeFactors -- prime factors of the integers
use Math::NumSeq::AllPrimeFactors; my $seq = Math::NumSeq::AllPrimeFactors->new; my ($i, $value) = $seq->next;
This is a list of the prime factors of the integers 2, 3, 4, etc
starting i=1 2, 3, 2, 2, 5, 2, 3, 7, 2, 2, 2, 3, 3, 2, 5, 11, ... \--/ \--/ \-----/ \--/ \--/ 4 5 6 7 8 9 10 11
The optional order
parameter (a string) can control the order of the primes within each integer,
"ascending" the default "descending"
For example "descending" rearranges the values to
# order => "descending" 2, 3, 2, 2, 5, 3, 2, 7, 2, 2, 2, 3, 3, 5, 2, 11, ... \--/ \--/ \-----/ \--/ \--/ 4 5 6 7 8 9 10 11
The first difference is 3,2 for 6 (instead of 2,3).
Option multiplicity => "distinct"
can give just one copy of each prime factor.
# multiplicity => "distinct" 2, 3, 2, 5, 2, 3, 7, 2, 3, 2, 5, 11, ... \--/ \--/ 4 5 6 7 8 9 10 11
Option on_values
can give the prime factors of just some integers,
"all" the default "composites" the non-primes from 4 onwards "odd" odd integers 3 onwards "even" even integers 2 onwards
"odd" is not simply a matter of filtering out 2s from the sequence, since it takes the other primes from the even integers too, such as the 3 from 6.
# on_values => "odd" 3, 5, 7, 3, 3, 11, 13, 3, 5, 17, \--/ \--/ 9 15
See "FUNCTIONS" in Math::NumSeq for behaviour common to all sequence classes.
$seq = Math::NumSeq::AllPrimeFactors->new ()
$seq = Math::NumSeq::AllPrimeFactors->new (order => $str, multiplicity => $str, on_values => $str)
Create and return a new sequence object.
$bool = $seq->pred($value)
Return true if $value
occurs in the sequence. This simply means $value
a prime, or for on_values=>'odd'
an odd prime.
Math::NumSeq, Math::NumSeq::PrimeFactorCount, Math::NumSeq::AllDigits
http://user42.tuxfamily.org/math-numseq/index.html
Copyright 2012, 2013, 2014 Kevin Ryde
Math-NumSeq is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.
Math-NumSeq is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with Math-NumSeq. If not, see <http://www.gnu.org/licenses/>.