Numbers n such that difference between upper and lower central divisors of n is 1.
1, 2, 4, 6, 12, 20, 30, 42, 56, 72, 90, 110, 132, 156, 182, 210, 240, 272, 306, 342, 380
2 seqfan posts
Mon Jun 7 16:43:30 CEST 2010 [seqfan] Re: A060798 Difference between upper and lower central divisors of n is 1