%I A087650
%S A087650 1,0,2,3,12,40,163,714,3426,17721,98254,580316,3633281,24011156,
%T A087650 166888166,1216070379,9264071768,73600798036,608476008123,5224266196934,
%U A087650 46499892038438,428369924118313,4078345814329010,40073660040755336
%N A087650 Sum_{k=0..n} (-1)^(n-k)*Bell(k).
%F A087650 E.g.f.: exp(-x)*((exp(x)-1)*exp(exp(x)-1)+1).
%F A087650 a(n)= (-1)^n + Bell(n) - A000296(n), with Bell(n)=A000110(n). Wolfdieter 
               Lang (wolfdieter.lang_AT_physik_DOT_uni-karlsruhe_DOT_de), Dec 01 
               2003
%t A087650 f[n_] := Sum[ StirlingS2[n, k], {k, 1, n}]; Table[(-1)^n + Sum[(-1)^(n 
               - k)*f[k], {k, 0, n}], {n, 0, 23}] (from Robert G. Wilson v)
%t A087650 Needs["DiscreteMath`Combinatorica`"]; Table[ Sum[(-1)^(n - k)*BellB[k], 
               {k, 0, n}], {n, 0, 23}] (from Robert G. Wilson v)
%Y A087650 Cf. A000110, A000296, A005001, A005493.
%Y A087650 Sequence in context: A012310 A082526 A151368 this_sequence A012514 A012511 
               A012309
%Y A087650 Adjacent sequences: A087647 A087648 A087649 this_sequence A087651 A087652 
               A087653
%K A087650 nonn
%O A087650 0,3
%A A087650 Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 23 2003