%I #15 Oct 21 2018 12:56:36

%S 1,1,-2,6,0,120,0,5040,0,362880,0,39916800,0,6227020800,0,

%T 1307674368000,0,355687428096000,0,121645100408832000,0,

%U 51090942171709440000,0,25852016738884976640000,0,15511210043330985984000000,0,10888869450418352160768000000,0,8841761993739701954543616000000

%N a(n) = n! except that a(2) = -2 and a(2n) = 0 for n > 2.

%C Same as A005212 for n > 2. - _Georg Fischer_, Oct 21 2018

%Y Cf. A005212, A009445.

%K sign,easy,less

%O 0,3

%A _Paul Curtz_, Jul 28 2007

%E Edited by _N. J. A. Sloane_, Jul 29 2007