a(n) = Sum{k=0..n} (-1)^k*A002893(k).

Terms

a(0) =0a(1) =-3a(2) =12a(3) =-81a(4) =558a(5) =-4095a(6) =31074a(7) =-241761a(8) =1915998a(9) =-15403839a(10) =125264226a(11) =-1028198769a(12) =8505440256a(13) =-70821126339a(14) =593013903996