G.f.: A(x) = (1 + 21*x + 3*x^2 - x^3)/(1-x)^5.

Terms

a(0) =1a(1) =26a(2) =123a(3) =364a(4) =845a(5) =1686a(6) =3031a(7) =5048a(8) =7929a(9) =11890a(10) =17171a(11) =24036a(12) =32773a(13) =43694a(14) =57135a(15) =73456a(16) =93041a(17) =116298a(18) =143659a(19) =175580a(20) =212541a(21) =255046a(22) =303623a(23) =358824a(24) =421225a(25) =491426a(26) =570051a(27) =657748a(28) =755189a(29) =863070