Expansion of g.f.: (1-4*x)/((1-5*x)*(1-x)^2).

Terms

a(0) =1a(1) =3a(2) =10a(3) =42a(4) =199a(5) =981a(6) =4888a(7) =24420a(8) =122077a(9) =610359a(10) =3051766a(11) =15258798a(12) =76293955a(13) =381469737a(14) =1907348644a(15) =9536743176a(16) =47683715833a(17) =238418579115