Numbers n such that sigma(n) / n is prime.
6, 28, 120, 496, 672, 8128, 523776, 33550336, 45981824
2 seqfan posts
Thu Feb 9 17:38:53 CET 2012 [seqfan] Re: Stumped on sums of perfect numbers
Thu Feb 9 01:39:04 CET 2012 [seqfan] Re: Stumped on sums of perfect numbers
Index of A-numbers in seqfan: by ascending order
by month
by frequency
by keyword
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