Expansion of g.f. x*(1 - x)*(1 + x)/(1 - x - 11*x^2 - x^3 + x^4).

Terms

a(0) =0a(1) =1a(2) =1a(3) =11a(4) =23a(5) =144a(6) =407a(7) =2003a(8) =6601a(9) =28897a(10) =103104a(11) =425569a(12) =1582009a(13) =6337475a(14) =24062039a(15) =94930704a(16) =364368599a(17) =1426330907a(18) =5505254161a(19) =21464332033a(20) =83084090112a(21) =323270665729