Expansion of (1+6*x)/(1-x-49*x^2).

Terms

a(0) =1a(1) =7a(2) =56a(3) =399a(4) =3143a(5) =22694a(6) =176701a(7) =1288707a(8) =9947056a(9) =73093699a(10) =560499443a(11) =4142090694a(12) =31606563401a(13) =234569007407