Two functions to programmatically search for matching sequences on the OEIS and to lookup a given sequence (by id) on the OEIS.

oeis.py

import requests
from lxml import html

def search(seq, n=10, m=10):
    """Search the OEIS for sequences matching seq and return a list of results.
    
    Args:
        seq: list of integers
        n: number of results to return.
        m: number of terms to return per result.
        
    Returns:
        List of OEIS results (if any) with each result represented as a tuple
        containing: sequence id, sequence URL, sequence description, sequence 
        elements from OEIS."""

    # Format the query from the sequence for OEIS
    q = '%2C'.join(map(str, seq))
    query = 'https://oeis.org/search?q={}&sort=&language=&go=Search'.format(q)
    
    # Submit the request with the query
    page = requests.get(query)
    tree = html.fromstring(page.content)

    # The xpaths to the resulting sequences.
    links_xpath =\
        '/html/body/center[2]/table/tr/td/table/tr/td/table/tr/td/a'
    
    # The xpath to the OEIS message box in case there are no results.
    msg_xpath =\
        '/html/body/center[2]/table/tr/td/table/tr[2]/td/table/tr/td//text()'
    
    # Get the sequence ids of the results.
    seq_ids = [link.attrib.get('href')[1:] for link in tree.xpath(links_xpath)[:n]]
    
    # If there are results then lookthem up and return their details.
    if len(seq_ids):
        return list(map(lambda ids: lookup(ids, m=m), seq_ids))
    
    # Otherwise print the OEIS message.
    else:
        return query, ''.join(''.join(tree.xpath(msg_xpath)).split('\n')).strip()
    
    
def lookup(seq_id, m=10):
    """Lookup the OEIS entry for sequence id and return list of elements.
    
    Args:
        seq_id: valid OEIS sequence id.
        m: number of terms to return.
        
    Returns:
        A tuple containing: (a) the sequence id; (b) sequence URL; 
        (c) the sequence description; and (d) its listed terms."""
    
    url = 'https://oeis.org/{}'.format(seq_id)
    
    page = requests.get(url)
    tree = html.fromstring(page.content)
    
    # Get the actual sequence terms
    desc_xpath =\
        '/html/body/center[2]/table/tr/td/center[2]/table/tr[3]/td/table/tr/td[3]/text()'
    terms_xpath =\
        '/html/body/center[2]/table/tr/td/center[2]/table/tr[4]/td/table/tr/td[2]/tt/text()'
    
    desc = tree.xpath(desc_xpath)
    terms = tree.xpath(terms_xpath)
    
    # If there are term then we have a valid sequence; return its id, url, 
    # description and terms.
    if len(terms):
        return (
            seq_id,                                    # Sequence id
            'https://oeis.org/{}'.format(seq_id),      # Sequence URL
            ''.join(desc).strip(),                     # Description
            list(map(int, terms[0].split(', ')[:m]))   # First m terms
        )
    
    # Otherwise return an error message.
    else:
        return "https://oeis.org/{} could not be found. It may be allocated for review.".format(seq_id)