Mikk Heidemaa, A Formal Presentation of Two Sequences, Their Gödel-Like Encoding, and a Commutative Group-Theoretic Result, (arXiv submission 6339673) (2025), 1-6. (oeis.org/A381080)
Abelian orders of hereditarily finite transitive sets.
Sequence: 1, 2, 3, 6, 12, 2^13868 * 3^7873 * 5^2012 * 7^1911, …
Conjecture: a(7) = 2^a ⋅ 3^b ⋅ 5^c ⋅ 7^d ⋅ 11^e ⋅13^f ⋅ ... ⋅ P^z.
Try to prove / disprove... (or to find a(7)...?)
Would like to know its factors / divisors... ;)
... a(5) has 19724 decimal digits.
