Expansion of c(3*x^2)/(1-x*c(3*x^2)), c(x) the g.f. of A000108.

Terms

a(0) =1a(1) =1a(2) =4a(3) =7a(4) =28a(5) =58a(6) =232a(7) =523a(8) =2092a(9) =4966a(10) =19864a(11) =48838a(12) =195352a(13) =492724a(14) =1970896a(15) =5068915a(16) =20275660a(17) =52955950a(18) =211823800a(19) =560198962a(20) =2240795848a(21) =5987822380a(22) =23951289520a(23) =64563867454a(24) =258255469816a(25) =701383563388