Expansion of 1/((1-2x)(1-3x)(1-7x)).

Terms

a(0) =1a(1) =12a(2) =103a(3) =786a(4) =5713a(5) =40656a(6) =286651a(7) =2012862a(8) =14109205a(9) =98822460a(10) =691932319a(11) =4844053578a(12) =33909961177a(13) =237374494824