Expansion of 1/((1-x)(1-4x)(1-5x)(1-6x)).

Terms

a(0) =1a(1) =16a(2) =167a(3) =1442a(4) =11193a(5) =81228a(6) =563179a(7) =3779974a(8) =24771725a(9) =159439280a(10) =1012078431a(11) =6355276746a(12) =39568060897a(13) =244679845972