erdős #418
Are there infinitely many positive integers not of the form ?
Worked, still open.
number theory · solved · formalized (Lean) · 0 attempts
use this record
vela registry pull vfr_37aec80d874a0239vela reproduce examples/erdos-problemsformal
AMS 11 · solved (literature)
theorem erdos_418 : answer(True) ↔ { (n - n.totient : ℕ) | n }ᶜ.Infiniteformal-conjectures/418.lean ↗oeis
A005278 — Noncototients: numbers k such that x - phi(x) = k has no solution.10,26,34,50,52,58,86,100,116,122,130,134,146,154,170,172,186,202,206,218,222,232,244,260,266,268,274,290,292,298,310,326A263958 — Prime Riesel numbers p that are not Mersenne primes such that 2*p is a noncototient.509203,2554843,9203917,9545351,10645867,11942443,14608183,15627133,15811777,16413457,21013423,21465637,25792993,30622663
status
solved