Expansion of (1-x)/(1-3*x-3*x^2-2*x^3).

Terms

a(0) =1a(1) =2a(2) =9a(3) =35a(4) =136a(5) =531a(6) =2071a(7) =8078a(8) =31509a(9) =122903a(10) =479392a(11) =1869903a(12) =7293691a(13) =28449566a(14) =110969577a(15) =432844811a(16) =1688342296a(17) =6585500475a(18) =25687217935a(19) =100194839822a(20) =390817174221