Expansion of (1-4x+x^2)/((1-x)(1-3x)(1-4x)).

Terms

a(0) =1a(1) =4a(2) =14a(3) =48a(4) =166a(5) =584a(6) =2094a(7) =7648a(8) =28406a(9) =107064a(10) =408574a(11) =1575248a(12) =6123846a(13) =23963944a(14) =94261454a(15) =372262848a(16) =1474702486a(17) =5855763224a(18) =23293912734a(19) =92788230448a(20) =369990660326