Series reversion of x*(1-5x)/(1-x) .

Terms

a(0) =1a(1) =4a(2) =36a(3) =404a(4) =5076a(5) =68324a(6) =963396a(7) =14046964a(8) =210062196a(9) =3204118724a(10) =49656709476a(11) =779690085204