In connection with the historical development of the classification of finite simple groups, I am interested in a particular aspect that seems to be less well-documented than the main narrative of discovery and confirmation. Specifically, I am referring to the question (posted 11 years ago) [Groups that do not exist][1], which asked whether there were finite simple groups conjectured at some point that turned out not to exist. To build upon that discussion, I am looking for a very specific kind of artifact from the history of group theory: explicit character tables for such conjectured but non-existent finite simple groups, if they ever were constructed. My understanding is that character tables were computed for many groups as part of the classification effort. **Question**: Could anyone provide references to or copies of explicit (complete) character tables developed for finite simple groups that were later shown not to exist? If possible, please elucidate the reasoning behind the exclusion. --- Regarding [Feit-Thompson Conjecture][2] mentioned in Dave Benson's [answer][3], which states that for any two distinct odd primes $p$ and $q$, the integer $\frac{p^q - 1}{p - 1}$ never divides $\frac{q^p - 1}{q - 1}$, I am unsure to what extent this has been verified. Below is a (parallelized) Python script that confirms the conjecture holds for $p, q < 25000$ within 90 minutes. It also identifies the pair $(p, q) = (17,3313)$ as noted in JoshuaZ's [comment][4], for the sole non-coprime example in this range. **Computation** ...$time python3 check_primes_parallel.py Pair not relatively prime: p=17, q=3313, gcd=112643 real 88m57.158s user 838m44.435s sys 0m9.762s **Code** # check_primes_parallel.py from sympy import primerange, gcd from multiprocessing import Pool import itertools def check_relative_prime_and_divisibility(pair): p, q = pair num1 = (pow(p, q) - 1) // (p - 1) num2 = (pow(q, p) - 1) // (q - 1) d = gcd(num1, num2) if d == 1: return None if num1 % num2 == 0: return f"Found divisible pair: p={p}, q={q}" else: return f"Pair not relatively prime: p={p}, q={q}, gcd={d}" def find_prime_pairs(max_prime, num_cpus=12): # Generate a list of odd primes up to max_prime primes = list(primerange(3, max_prime)) # Generate all unique combinations of two primes prime_pairs = list(itertools.combinations(primes, 2)) # Create a pool of workers with the desired number of CPUs with Pool(processes=num_cpus) as pool: # Map the function over the prime pairs, distributed across the workers results = pool.map(check_relative_prime_and_divisibility, prime_pairs) # Filter out None results and print the rest for result in filter(None, results): print(result) # Set a maximum prime number limit according to your computational power max_prime = 25000 # You can adjust this value find_prime_pairs(max_prime) [1]: https://mathoverflow.net/questions/115735/groups-that-do-not-exist [2]: https://en.wikipedia.org/wiki/Feit–Thompson_conjecture [3]: https://mathoverflow.net/a/460055 [4]: https://mathoverflow.net/questions/460049/request-for-explicit-character-tables-of-conjectured-non-existent-finite-simple#comment1192037_460055