p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - 2 S - 2 S^2.

Terms

a(0) =2a(1) =8a(2) =28a(3) =98a(4) =344a(5) =1208a(6) =4240a(7) =14884a(8) =52248a(9) =183408a(10) =643824a(11) =2260040a(12) =7933504a(13) =27849280a(14) =97760384a(15) =343171984a(16) =1204649632a(17) =4228727296a(18) =14844261824a(19) =52108375328a(20) =182918006400a(21) =642104016000