a(1)=1, a(2)=2; a(n) = abs((n-1)*a(n-1) - n*a(n-2)), n > 2.
A192264
a(1)=1, a(2)=2; a(n) = abs((n-1)*a(n-1) - n*a(n-2)), n > 2.
Terms
- a(0) =1a(1) =2a(2) =1a(3) =5a(4) =15a(5) =45a(6) =165a(7) =795a(8) =4875a(9) =35925a(10) =305625a(11) =2930775a(12) =31196175a(13) =364519425a(14) =4635329325a(15) =63697629075a(16) =940361466675
External references
- oeis: A192264