A250106 Column 2 of triangle in A250104 (or A124323).

1, 0, 6, 10, 60, 231, 1148, 5832, 32175, 188375, 1169652, 7663734, 52808847, 381494400, 2881338840, 22696790440, 186058768140, 1584156272157, 13984151627030, 127779961705620, 1206805491491985, 11764472685724561, 118230099056654664

Offset

2,3

Links

Table of n, a(n) for n=2..24.

T. Mansour, A. O. Munagi, Set partitions with circular successions, European Journal of Combinatorics, 42 (2014), 207-216.

Maple

A250106 := proc(n)
    A124323(n, 2) ;
end proc:
seq(A250106(n), n=2..50) ; # R. J. Mathar, Jan 22 2015

Mathematica

t[n_, k_] := Binomial[n, k] ((-1)^(n-k) + Sum[(-1)^(j-1) BellB[n-k-j], {j, 1, n-k}]);
Table[t[n, 2], {n, 2, 24}] (* Jean-François Alcover, Apr 03 2020 *)

Crossrefs

Cf. A250104, A124323.

Sequence in context: A136848 A136849 A136847 * A230827 A111484 A119041

Adjacent sequences: A250103 A250104 A250105 * A250107 A250108 A250109

Keyword

nonn

Author

N. J. A. Sloane, Nov 16 2014

Status

approved