A250105 Column 1 of triangle in A250104 (or A124323).

0, 0, 3, 4, 20, 66, 287, 1296, 6435, 34250, 194942, 1179036, 7544121, 50865920, 360167355, 2670210640, 20673196460, 166753291806, 1398415162703, 12169520162440, 109709590135635, 1022997624845614, 9852508254721222, 97880299543896216, 1001841501018883425

Offset

1,3

Links

Table of n, a(n) for n=1..25.

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

Mathematica

a[n_] := n*(Sum[(-1)^(j-1)*BellB[n-j-1], {j, 1, n-1}]-(-1)^n); a[1] = 0; Table[a[n], {n, 1, 25}] (* Jean-François Alcover, Dec 09 2014 *)

Crossrefs

Cf. A250104, A124323.

Sequence in context: A067281 A326424 A151357 * A009169 A265710 A322673

Adjacent sequences: A250102 A250103 A250104 * A250106 A250107 A250108

Keyword

nonn

Author

N. J. A. Sloane, Nov 16 2014

Status

approved