X^m=X rings without normal forms: integers m > 1 for which there exist a prime p and integers a,b > 0 such that both p^a-1 and p^b-1 divide m-1 but p^lcm(a,b)-1 does not divide m-1.

A019508

X^m=X rings without normal forms: integers m > 1 for which there exist a prime p and integers a,b > 0 such that both p^a-1 and p^b-1 divide m-1 but p^lcm(a,b)-1 does not divide m-1.