NAME
Math::OEIS::Stripped  read the OEIS stripped file
SYNOPSIS
my @values = Math::OEIS::Stripped>anum_to_values('A123456');
DESCRIPTION
This is an interface to the big OEIS stripped file. The file should be downloaded and unzipped to ~/OEIS/stripped,
cd ~/OEIS
wget http://oeis.org/stripped.gz
gunzip stripped.gz
stripped is a very large file containing each Anumber and its sample values. There's usually about 180 characters worth of sample values but possibly less or more.
The stripped file is sorted by Anumber so anum_to_values()
is a text file binary search (currently implemented with Search::Dict).
Terms of use for the stripped file data can be found at (Creative Commons Attribution NonCommercial 3.0 at the time of writing)
FUNCTIONS
@values = Math::OEIS::Stripped>anum_to_values($anum)
$values_str = Math::OEIS::Stripped>anum_to_values_str($anum)

Return the values from the stripped file for
$anum
(a string) such as "A000001".anum_to_values()
returns a list of values, or an empty list if no such Anumber.Values bigger than a Perl integer are converted to
Math::BigInt
so as to be exact in numeric operations, such as comparisons==
or>=
.anum_to_values_str()
returns a string like "1,2,3,4", orundef
if no such Anumber. The stripped file has leading and trailing commas on its values list but these are removed here for convenience of subsequentsplit
or similar.In the past, draft sequences were in the stripped with an empty values list ",,". The return for them is an empty list, reckoning "no such Anumber" when no values yet.
If running in
perl T
taint mode then$values_str
and each value string in@values
is tainted in the usual way for reading from a file. Values converted toMath::BigInt
do not keep a notion of taintedness, butMath::BigInt
should validate as digits which is in the spirit of untainting after checking. Math::OEIS::Stripped>close()

Close the stripped file handle, or do nothing if already closed or never opened.
Oopery
$obj = Math::OEIS::Stripped>new (key => value, ...)

Create and return a new
Math::OEIS::Stripped
object to read an OEIS stripped file. The optional key/value parameters can befilename => $filename # default ~/OEIS/stripped fh => $filehandle use_bigint => string "if_necessary", # default 0, # never 1, # always bigint_class => $classname # default "Math::BigInt"
filename
defaults to ~/OEIS/stripped perMath::OEIS>local_directories()
. Another filename can be given, or an open filehandle. If a handle is given thenfilename
may be used for diagnostics and so can be helpfully given too.use_bigint
controls conversion of values to bignum objects inanum_to_values()
etc. Default"if_necessary"
converts values bigger than a Perl integer, or option 1 or 0 for always or never convert. When not converted, each value is a string suitable for any string operation but possibly not numeric operations.bigint_class
is the module name for bignum conversion. It isrequire
'd when needed and values are created by$classname>new("123")
. If the class has runtime options, such asMath::BigInt
choice of backends, then set that up from mainline code. @values = $obj>anum_to_values($anum)
$values_str = $obj>anum_to_values_str($anum)

Return the values from the stripped file for an
$anum
string such as "A000001", like the class method described above. $filename = $obj>filename()

Return the filename from
$obj
. $filename = Math::OEIS::Stripped>default_filename()
$filename = $obj>default_filename()

Return the default filename which is used if no
filename
orfh
option is given.default_filename()
can be called either as a class method or object method. $obj>close()

Close the stripped file handle, or do nothing if already closed.
($anum,$values_str) = Math::OEIS::Stripped>line_split_anum($line)

Split a line of the stripped file into Anumber and values string.
$line
should be likeA123456 ,1,6,9,23,65,17,5,997,
Leading and trailing comma (and any trailing newline) are stripped so
$values_str
is like "1,2,3".If
$line
is not Anumber and values like this then return an empty list. The stripped file starts with some comment lines (#
) and they get this empty return.In the past, draft sequences were included in the stripped file with empty values list. They are reckoned nonlines since no values, so empty return.
@values = Math::OEIS::Stripped>values_split($values_str)
@values = $obj>values_split($values_str)

$values_str
is a string of integers and commas like "123,456,789". Return them split to a list of integers.This a
split()
on commas, but with theuse_bigint
option applied to the result. Seenew()
above on that option.
SEE ALSO
Math::OEIS
, Math::OEIS::Names
OEIS files page http://oeis.org/allfiles.html
HOME PAGE
http://user42.tuxfamily.org/mathoeis/index.html
LICENSE
Copyright 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2019 Kevin Ryde
MathOEIS 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.
MathOEIS 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 MathOEIS. If not, see http://www.gnu.org/licenses/.