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A275290 Number of set partitions of [n] with symmetric block size list of length five. 2

%I #10 Aug 02 2016 07:40:04

%S 1,3,22,86,470,2066,10299,47503,229792,1081851,5189068,24671320,

%T 118223765,565269659,2713032552,13022313334,62644482305,301600159952,

%U 1454293747517,7019496361595,33922782653124,164099194834163,794642770006896,3851565096708617

%N Number of set partitions of [n] with symmetric block size list of length five.

%H Alois P. Heinz, <a href="/A275290/b275290.txt">Table of n, a(n) for n = 5..500</a>

%H Vaclav Kotesovec, <a href="/A275290/a275290.txt">Recurrence (of order 7)</a>

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Partition_of_a_set">Partition of a set</a>

%F a(n) ~ 5^n / (96*Pi*n). - _Vaclav Kotesovec_, Aug 02 2016

%e a(6) = 3: 1|2|34|5|6, 1|2|35|4|6, 1|2|36|4|5.

%e a(7) = 22: 12|3|4|5|67, 13|2|4|5|67, 1|23|4|56|7, 1|23|4|57|6, 14|2|3|5|67, 1|24|3|56|7, 1|24|3|57|6, 1|2|345|6|7, 1|2|346|5|7, 1|2|347|5|6, 15|2|3|4|67, 1|25|3|46|7, 1|25|3|47|6, 1|2|356|4|7, 1|2|357|4|6, 1|26|3|45|7, 1|27|3|45|6, 16|2|3|4|57, 1|26|3|47|5, 1|2|367|4|5, 1|27|3|46|5, 17|2|3|4|56.

%Y Column k=5 of A275281.

%K nonn

%O 5,2

%A _Alois P. Heinz_, Jul 22 2016

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