sigma(n) = sum of divisors of n. Also called sigma_1(n).
1, 3, 4, 7, 6, 12, 8, 15, 13, 18, 12, 28, 14, 24, 24, 31, 18, 39, 20, 42, 32, 36, 24, 60, 31
Index of A-numbers in seqfan: by ascending order
by month
by frequency
by keyword
23 seqfan posts
Sat Jul 9 16:18:41 CEST 2011 [seqfan] gcd(n, sigma_2(n))
Fri Oct 29 05:35:16 CEST 2010 [seqfan] Implementing first 500 sequences in Java
Wed Oct 6 08:40:02 CEST 2010 [seqfan] A175874: more terms?
Mon Sep 27 01:30:55 CEST 2010 [seqfan] Sigma(T(n))=T(m)
Sun Sep 26 06:48:14 CEST 2010 [seqfan] Re: n-th number whose sum of divisors is a n-gonal number
Sun Sep 26 05:22:18 CEST 2010 [seqfan] Re: n-th number whose sum of divisors is a n-gonal number
Sat Sep 25 22:43:13 CEST 2010 [seqfan] n-th number whose sum of divisors is a n-gonal number
Tue Aug 24 11:02:09 CEST 2010 [seqfan] Re: A180268
Tue Aug 24 00:11:20 CEST 2010 [seqfan] Re: A180268
Mon Aug 23 23:11:02 CEST 2010 [seqfan] Re: A180268
Mon Aug 23 23:07:51 CEST 2010 [seqfan] Re: A180268
Mon Aug 23 22:23:04 CEST 2010 [seqfan] Re: A180268
Mon Aug 23 22:07:27 CEST 2010 [seqfan] A180268
Mon Jun 28 21:36:52 CEST 2010 [seqfan] What defines A133992
Tue Mar 16 06:12:11 CET 2010 [seqfan] Re: GF for A147843?
Mon Mar 15 15:11:00 CET 2010 [seqfan] Re: GF for A147843?
Mon Feb 22 22:02:17 CET 2010 [seqfan] Re: A173279 and A173280
Tue Jan 12 21:17:40 CET 2010 [seqfan] Re: naive sequence generator
Tue Jan 12 21:10:30 CET 2010 [seqfan] Re: naive sequence generator
Fri Jul 10 02:18:57 CEST 2009 [seqfan] sum of divisors and integer partitions
Mon Jun 22 07:51:43 CEST 2009 [seqfan] Re: A151659
Mon Jun 22 01:18:07 CEST 2009 [seqfan] Re: A151659
Sun Jun 21 23:31:46 CEST 2009 [seqfan] Re: A151659
Index of A-numbers in seqfan: by ascending order
by month
by frequency
by keyword
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