3 ms·
Curious about base 2. Obviously if you hit a 0 it's immediately not prime, but maybe adjust the rules so: - you drill through as many 0's on the right. - you
by throwawaymaths 1y ago
Curious about base 2. Obviously if you hit a 0 it's immediately not prime, but maybe adjust the rules so:
- you drill through as many 0's on the right.
- you finish on 1.
3, 5, 7, 11, 13, 15, 17 are all right truncatable, 19 is the first non-truncatable prime in this scheme.
- nh23423fefe 1y agoi dont think smaller radixes make the problem more interesting. the problem is interesting because base 10 has a large branching factor
- throwawaymaths 1y agoI think in the base2 reformulation I propose we do not know for certain if the list of numbers terminates, as all Fermat primes are in the set and we don't know if there are infinitely many Fermat primes. For base-10 and the original rules the set is provably closed. "Drilling through zeros" makes the branching unbounded.