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

Terms

a(0) =1a(1) =3a(2) =4a(3) =21a(4) =56a(5) =282a(6) =984a(7) =4813a(8) =19280a(9) =93150a(10) =403672a(11) =1945954a(12) =8845360a(13) =42766292a(14) =200419504a(15) =974134461a(16) =4659558048a(17) =22785183670a(18) =110564976792a(19) =543935554390