This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A250105 #14 Dec 10 2014 04:01:28
%S A250105 0,0,3,4,20,66,287,1296,6435,34250,194942,1179036,7544121,50865920,
%T A250105 360167355,2670210640,20673196460,166753291806,1398415162703,
%U A250105 12169520162440,109709590135635,1022997624845614,9852508254721222,97880299543896216,1001841501018883425
%N A250105 Column 1 of triangle in A250104 (or A124323).
%H A250105 T. Mansour, A. O. Munagi, <a href="http://dx.doi.org/10.1016/j.ejc.2014.06.008">Set partitions with circular successions</a>, European Journal of Combinatorics, 42 (2014), 207-216.
%t A250105 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 *)
%Y A250105 Cf. A250104, A124323.
%K A250105 nonn
%O A250105 1,3
%A A250105 _N. J. A. Sloane_, Nov 16 2014