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.

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

Alois P. Heinz, Table of n, a(n) for n = 0..300

Formula

a(n) = A270953(n,n-floor((1+sqrt(max(0,8*n-7)))/2)).

Crossrefs

Cf. A083920, A270953.

Sequence in context: A060539 A163269 A103905 * A103209 A089900 A138533

Adjacent sequences: A270964 A270965 A270966 * A270968 A270969 A270970

Keyword

nonn

Author

Alois P. Heinz, Mar 26 2016

Status

approved