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Total number of blocks in all set partitions of [n] with alternating parity of elements.
1

%I #7 Jun 10 2018 13:33:07

%S 0,1,3,8,20,53,136,383,1067,3292,10162,34586,118332,441898,1660947,

%T 6745710,27575425,120801230,532530170,2499230441,11800052796,

%U 58992236094,296630364605,1572128197439,8378539879636,46882666240016,263735138346443,1552510947814406

%N Total number of blocks in all set partitions of [n] with alternating parity of elements.

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

%F a(n) = Sum_{k=0..n} k * A274581(n,k).

%Y Cf. A274581.

%K nonn

%O 0,3

%A _Alois P. Heinz_, Jun 10 2018