Number of self-inverse permutations on n letters, also known as involutions; number of Young tableaux with n cells.
1, 1, 2, 4, 10, 26, 76, 232, 764, 2620, 9496, 35696, 140152, 568504, 2390480
10 seqfan posts
Wed Jul 25 16:48:09 CEST 2012 [seqfan] Re: collapsing permutations to mere Set Partitions(longish)
Wed Jul 25 14:37:17 CEST 2012 [seqfan] Re: collapsing permutations to mere Set Partitions (longish)
Wed Jul 25 10:34:45 CEST 2012 [seqfan] collapsing permutations to mere Set Partitions (longish)
Sat Oct 29 12:53:11 CEST 2011 [seqfan] Re: A construction problem
Sat Oct 29 08:41:31 CEST 2011 [seqfan] Re: A construction problem
Wed Jan 26 15:24:23 CET 2011 [seqfan] Experiment: period of a(n) mod p (after ditching rational expressions and linear recurrences)
Fri Oct 29 05:35:16 CEST 2010 [seqfan] Implementing first 500 sequences in Java
Fri Mar 26 23:29:32 CET 2010 [seqfan] Re: Sequences for Orderings
Fri Oct 2 05:21:01 CEST 2009 [seqfan] A055814: permutations with all cycles of length 2 or 3
Wed Jun 24 09:42:04 CEST 2009 [seqfan] suggest comment for A000085 (Involutions)
Index of A-numbers in seqfan: by ascending order
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