V-Demon / oeis-search

search offline dumps of the OEIS

oeis-search

A command-line Python program that searches offline dumps of the On-Line Encyclopedia of Integer Sequences (OEIS) and prints sequences that match all specified criteria.

Table of contents:

• Requirements
• Command line arguments
• Example 1
• Example 2

Requirements

Requires the files names and stripped from here. Download names.gz and stripped.gz and uncompress them in the same directory as this program. (Use gunzip on Linux or 7-Zip on Windows to uncompress.)

Command line arguments

All arguments are optional.

How to search the names file

Tip: to speed up the search, specify at least one of these options.

• --minanum INTEGER: Find sequences whose A-number is greater than or equal to INTEGER. INTEGER must be 0 or greater. The default is 0.
• --maxanum INTEGER: Find sequences whose A-number is less than or equal to INTEGER. INTEGER must be greater than or equal to --minanum. The default is 999999.
• --descr TEXT: Find sequences whose description contains TEXT case-insensitively.

How to search the terms file

• --searchfirst INTEGER: When searching, only consider INTEGER first terms in each sequence. (The rest are ignored.) INTEGER must be 0 or greater. 0 means all terms are searched. The default is 0. This option affects all other options in this section.
• --terms LIST: Find sequences that contain all terms specified by LIST, in any order, possibly with other terms in between. LIST is a comma-separated list of integers, e.g. "1,2,3".
• --consec LIST: Find sequences that contain all terms specified by LIST, in the specified order, with no other terms in between. LIST is a comma-separated list of integers, e.g. "1,2,3".
• --noterms LIST: Find sequences that do not contain any term specified by LIST. LIST is a comma-separated list of integers, e.g. "1,2,3".
• --minmin INTEGER: Find sequences whose smallest term is INTEGER or greater.
• --minmax INTEGER: Find sequences whose smallest term is INTEGER or smaller.
• --maxmin INTEGER: Find sequences whose greatest term is INTEGER or greater.
• --maxmax INTEGER: Find sequences whose greatest term is INTEGER or smaller.
• --termorder ORDER: Find sequences whose terms are in ORDER. ORDER is one of the following:
  • a = (non-strictly) ascending (e.g. 1, 1, 2, …)
  • d = (non-strictly) descending (e.g. 2, 2, 1, …)
  • n = neither ascending or descending (e.g. 1, 2, 1, …)
  • y = any (the default).
• --distinct DISTINCT: Find sequences with distinct values? DISTINCT is one of the following:
  • y = yes (find sequences whose values are all distinct)
  • n = no (find sequences containing at least some duplicate values)
  • a = any (the default)

How to output the results

• --sort ORDER: Print results in ORDER. ORDER is one of the following:
  • a = by A-number (the default)
  • d = by description
  • t = by terms.
• --format FORMAT: Print information about each sequence in FORMAT. FORMAT is one of the following:
  • m = A-number, description and terms on multiple lines (the default)
  • adt = A-number, description and terms on a single line
  • ad = A-number and description on a single line
  • at = A-number and terms on a single line
  • a = A-number on a single line.
• --printfirst INTEGER: Do not print more than INTEGER first terms of each sequence. INTEGER must be 0 or greater. 0 means all terms are printed. The default is 0.

Miscellaneous options

• --namefile FILE: Read A-numbers and names of sequences from FILE. Default: names.
• --termfile FILE: Read A-numbers and terms of sequences from FILE. Default: stripped.
• --quiet: Do not print status messages ("reading file..." etc.).
• -h or --help: print a short summary of these command line arguments and exit.

Example 1

$ python3 oeissearch.py --descr "prime" --terms "1,4,5,9,64" --termorder a \
--distinct y --sort d
Searching 'names'...
Searching 'stripped'...
Found 256 sequence(s).

A051038: 11-smooth numbers: numbers whose prime divisors are all <= 11.
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 18, 20, 21, 22, 24, 25, 27,
28, 30, 32, 33, 35, 36, 40, 42, 44, 45, 48, 49, 50, 54, 55, 56, 60, 63, 64, 66,
70, 72, 75, 77, 80, 81, 84, 88, 90, 96, 98, 99, 100, 105, 108, 110, 112, 120,
121, 125, 126, 128, 132, 135, 140

A080197: 13-smooth numbers: numbers whose prime divisors are all <= 13.
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 20, 21, 22, 24, 25,
26, 27, 28, 30, 32, 33, 35, 36, 39, 40, 42, 44, 45, 48, 49, 50, 52, 54, 55, 56,
60, 63, 64, 65, 66, 70, 72, 75, 77, 78, 80, 81, 84, 88, 90, 91, 96, 98, 99,
100, 104, 105, 108, 110, 112, 117, 120

(snip)

Example 2

$ python3 oeissearch.py --consec 19,84 --maxmax 200 --format ad --quiet
A065266: A065264 conjugated with A059893, inverse of A065265.
A065290: A065288 conjugated with A059893, inverse of A065289.
A173823: a(n) shows the digit sum of a(n+1) + a(n+2).
A191514: Lehrer's elementary sequence.
A294886: Sum of deficient proper divisors of n.
A340587: a(n) is the least root of A340586(n).