G.f.: -2*(-2 - 11*x - 4*x^2 + x^3)/(x - 1)^4.

Terms

a(0) =4a(1) =38a(2) =136a(3) =330a(4) =652a(5) =1134a(6) =1808a(7) =2706a(8) =3860a(9) =5302a(10) =7064a(11) =9178a(12) =11676a(13) =14590a(14) =17952a(15) =21794a(16) =26148a(17) =31046a(18) =36520a(19) =42602a(20) =49324a(21) =56718a(22) =64816a(23) =73650a(24) =83252a(25) =93654a(26) =104888a(27) =116986a(28) =129980a(29) =143902