%N Positive integers x that are (x-1)/log(x-1) smooth, that is, if a prime p divides x, then p <= (x-1)/log(x-1).
%C This sequence is a monoid under multiplication, since if x and y are terms in the sequence and p < x/log(x), then p < xy/log(xy). However, if a term in the sequence is multiplied by a number outside the sequence, the result need not be in the sequence.
%e 1 is in the sequence because no primes divide 1, 2 is in the sequence since 2 divides 2 and 2 < 2/log(2) ~ 2.9, but 10 is not in the sequence since 5 divides 10 and 5 is not less than 10/log(10) ~ 4.34.
%t ok[n_] := AllTrue[First /@ FactorInteger[n], # Log[n] <= n &]; Select[ Range, ok] (* _Giovanni Resta_, Jun 30 2018 *)
%o (PARI) isok(n) = my(f=factor(n)); for (k=1, #f~, if (f[k,1] >= n/log(n), return(0))); return (1); \\ _Michel Marcus_, Jul 02 2018
%Y Cf. A050500.
%A _Richard Locke Peterson_, Jun 29 2018