Signed Stirling numbers of the second kind.

Terms

a(0) =1a(1) =1a(2) =-1a(3) =1a(4) =-3a(5) =1a(6) =1a(7) =-7a(8) =6a(9) =-1a(10) =1a(11) =-15a(12) =25a(13) =-10a(14) =1a(15) =1a(16) =-31a(17) =90a(18) =-65a(19) =15a(20) =-1a(21) =1a(22) =-63a(23) =301a(24) =-350a(25) =140a(26) =-21a(27) =1a(28) =1a(29) =-127