OFFSET
2,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 2..250
Wikipedia, Partition of a set
EXAMPLE
a(3) = 6 because the number of entries in the second last blocks of all set partitions of [3] (123, 12|3, 13|2, 1|23, 1|2|3) is 0+2+2+1+1 = 6.
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, May 09 2017
STATUS
approved