G.f. A(x) satisfies: Sum_{n>=1} ( A(x) - (-1)^n * A(-x) )^n * (-1)^n / n = 0.

Terms

a(0) =1a(1) =1a(2) =1a(3) =4a(4) =10a(5) =33a(6) =105a(7) =354a(8) =1214a(9) =4206a(10) =14846a(11) =52750a(12) =189516a(13) =686745a(14) =2506913a(15) =9211226a(16) =34036230a(17) =126426446a(18) =471769950a(19) =1767460752a(20) =6645539212a(21) =25076120890a(22) =94937019050a(23) =360268374124