a(0) = 0, a(1) = 1, and for n>=2, a(n) = (n-2)*a(n-1) - (n-1)*a(n-2).

A232845

a(0) = 0, a(1) = 1, and for n>=2, a(n) = (n-2)*a(n-1) - (n-1)*a(n-2).

Terms

    a(0) =0a(1) =1a(2) =0a(3) =-2a(4) =-4a(5) =-4a(6) =4a(7) =44a(8) =236a(9) =1300a(10) =8276a(11) =61484a(12) =523804a(13) =5024036a(14) =53478980a(15) =624890236a(16) =7946278604a(17) =109195935284

External references