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A270967
Number of set partitions of [n] having the maximal possible number of pairs (m,m+1) such that m+1 is in some block b and m is in block b+1.
2
1, 1, 2, 1, 6, 3, 1, 21, 10, 4, 1, 76, 36, 15, 5, 1, 281, 133, 57, 21, 6, 1, 1052, 499, 218, 85, 28, 7, 1, 3974, 1890, 838, 339, 121, 36, 8, 1, 15113, 7207, 3233, 1343, 505, 166, 45, 9, 1, 57774, 27622, 12509, 5302, 2069, 726, 221, 55, 10, 1, 221781, 106289
OFFSET
0,3
LINKS
FORMULA
a(n) = A270953(n,n-floor((1+sqrt(max(0,8*n-7)))/2)).
CROSSREFS
Sequence in context: A060539 A163269 A103905 * A103209 A089900 A138533
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Mar 26 2016
STATUS
approved