Expansion of (1+4x+7x^2)/((1-x)^2*(1-x^2)).

Terms

a(0) =1a(1) =6a(2) =19a(3) =36a(4) =61a(5) =90a(6) =127a(7) =168a(8) =217a(9) =270a(10) =331a(11) =396a(12) =469a(13) =546a(14) =631a(15) =720a(16) =817a(17) =918a(18) =1027a(19) =1140a(20) =1261a(21) =1386a(22) =1519a(23) =1656a(24) =1801a(25) =1950a(26) =2107a(27) =2268a(28) =2437a(29) =2610