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

Terms

a(0) =1a(1) =8a(2) =47a(3) =250a(4) =1281a(5) =6468a(6) =32467a(7) =162590a(8) =813461a(9) =4068328a(10) =20343687a(11) =101722530a(12) =508620841a(13) =2543120588a(14) =12715635707a(15) =63578244070a(16) =317891351421