The second left hand column of triangle A167580.

Terms

a(0) =-1a(1) =0a(2) =28a(3) =192a(4) =880a(5) =3328a(6) =11200a(7) =34816a(8) =102144a(9) =286720a(10) =777216a(11) =2048000a(12) =5271552a(13) =13303808a(14) =33013760a(15) =80740352a(16) =194969600a(17) =465567744a(18) =1100742656a(19) =2579496960a(20) =5996806144a(21) =13841203200a(22) =31738298368a(23) =72343355392a(24) =163997286400