Busy Beaver Frontier
n
Σ(n)
BB(1)
1
✓
1962
BB(2)
6
✓
1962
BB(3)
21
✓
1965
BB(4)
107
✓
1983
BB(5)
47,176,870
✓
2024
BB(6)
≥ 10↑↑15
≥
BB(7)
∞?
∞
BB(5) proven by bbchallenge.org, 2024