G.f.: (1+8*x+22*x^2+8*x^3+x^4)/(1-x)^6.

Terms

a(0) =1a(1) =14a(2) =91a(3) =364a(4) =1085a(5) =2666a(6) =5719a(7) =11096a(8) =19929a(9) =33670a(10) =54131a(11) =83524a(12) =124501a(13) =180194a(14) =254255a(15) =350896a(16) =474929a(17) =631806a(18) =827659a(19) =1069340a(20) =1364461a(21) =1721434a(22) =2149511a(23) =2658824a(24) =3260425a(25) =3966326a(26) =4789539a(27) =5744116a(28) =6845189a(29) =8109010