Lucas-version of A165293.

Terms

a(0) =2a(1) =10a(2) =-2a(3) =100a(4) =-30a(5) =2a(6) =1000a(7) =-400a(8) =50a(9) =-2a(10) =10000a(11) =-5000a(12) =900a(13) =-70a(14) =2a(15) =100000a(16) =-60000a(17) =14000a(18) =-1600a(19) =90a(20) =-2