Expansion of the solution of a functional equation.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =8a(6) =18a(7) =41a(8) =95a(9) =227a(10) =549a(11) =1344a(12) =3332a(13) =8332a(14) =21000a(15) =53310a(16) =136140a(17) =349536a(18) =901758a(19) =2336356a(20) =6076642a(21) =15860182a(22) =41527148a(23) =109048082a(24) =287119014a(25) =757829438a(26) =2004774538a(27) =5314615208a(28) =14116453336a(29) =37563744952