Expansion of (sqrt(1-4x^2) - sqrt(1-4x))/(2x).

Terms

a(0) =1a(1) =0a(2) =2a(3) =4a(4) =14a(5) =40a(6) =132a(7) =424a(8) =1430a(9) =4848a(10) =16796a(11) =58744a(12) =208012a(13) =742768a(14) =2674440a(15) =9694416a(16) =35357670a(17) =129643360a(18) =477638700a(19) =1767258328a(20) =6564120420a(21) =24466250224a(22) =91482563640a(23) =343059554864