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

Terms

a(0) =1a(1) =1a(2) =3a(3) =9a(4) =29a(5) =97a(6) =333a(7) =1165a(8) =4135a(9) =14845a(10) =53791a(11) =196417a(12) =721887a(13) =2667941a(14) =9907851a(15) =36950465a(16) =138320021a(17) =519515209a(18) =1957091277a(19) =7392602917a(20) =27992976565a(21) =106236268337a(22) =404005515873