Expansion of 1/((1-x)(1-2x)(1-6x)(1-7x)).

Terms

a(0) =1a(1) =16a(2) =173a(3) =1592a(4) =13461a(5) =108192a(6) =841261a(7) =6392584a(8) =47771141a(9) =352537328a(10) =2576599389a(11) =18689228376a(12) =134742802741a(13) =966708860224