Perfect numbers n: n is equal to the sum of the proper divisors of n.
6, 28, 496, 8128, 33550336, 8589869056, 137438691328, 2305843008139952128
Index of A-numbers in seqfan: by ascending order
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12 seqfan posts
Thu Feb 10 17:23:07 CET 2011 [seqfan] Re: Should this be cited as a link to A000396?
Thu Feb 10 05:47:26 CET 2011 [seqfan] Should this be cited as a link to A000396?
Wed Nov 3 22:15:01 CET 2010 [seqfan] Re: Near-perfect numbers
Mon Nov 1 19:06:41 CET 2010 [seqfan] Near-perfect numbers
Fri Oct 29 20:13:58 CEST 2010 [seqfan] Re: Who understands Granville numbers?
Fri Oct 29 05:35:16 CEST 2010 [seqfan] Implementing first 500 sequences in Java
Fri Jul 9 16:48:33 CEST 2010 [seqfan] Re: A083207 On an observation of Frank Buss.
Tue Jun 15 11:34:23 CEST 2010 [seqfan] an interesting but difficult sequence
Fri Mar 12 10:09:44 CET 2010 [seqfan] editing A000217 Triangular numbers (long message)
Tue Apr 21 23:36:56 CEST 2009 [seqfan] comments about perfect numbers
Thu Dec 18 23:36:26 CET 2008 [seqfan] Re: Mathematica and aspiring numbers
Thu Dec 18 23:20:34 CET 2008 [seqfan] Re: Mathematica and aspiring numbers
Index of A-numbers in seqfan: by ascending order
by month
by frequency
by keyword
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