Convolution of the central binomial coefficients A000984(n) and (-2)^n.

Terms

a(0) =1a(1) =0a(2) =6a(3) =8a(4) =54a(5) =144a(6) =636a(7) =2160a(8) =8550a(9) =31520a(10) =121716a(11) =462000a(12) =1780156a(13) =6840288a(14) =26436024a(15) =102245472a(16) =396589446a(17) =1540427328a(18) =5994280644a(19) =23356702512a(20) =91133123796a(21) =355991626848