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A250105 Column 1 of triangle in A250104 (or A124323). 2
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 (list; graph; refs; listen; history; text; internal format)
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-Fran├žois 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

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Last modified February 26 18:29 EST 2020. Contains 332293 sequences. (Running on oeis4.)