Expansion of x + sqrt(1-2x-3x^2).

Terms

a(0) =1a(1) =0a(2) =-2a(3) =-2a(4) =-4a(5) =-8a(6) =-18a(7) =-42a(8) =-102a(9) =-254a(10) =-646a(11) =-1670a(12) =-4376a(13) =-11596a(14) =-31022a(15) =-83670a(16) =-227268a(17) =-621144a(18) =-1706934a(19) =-4713558a(20) =-13072764a(21) =-36398568a(22) =-101704038a(23) =-285095118a(24) =-801526446a(25) =-2259520830a(26) =-6385455594a(27) =-18086805002