A055371 Column 1 of triangle A055370.
1, -1, 1, -1, 0, 5, -18, 27, 67, -496, 496, 6963, -24246, -148002, 1138045, 3360042, -58828040, -33243252, 3312139446, -5235582541, -204462055464, 726496668085, 14922365946662, -84161948692035, -1310383972147810
Offset: 1