Expansion of 1/(1-4x-4x^2-4x^3).

Terms

a(0) =1a(1) =4a(2) =20a(3) =100a(4) =496a(5) =2464a(6) =12240a(7) =60800a(8) =302016a(9) =1500224a(10) =7452160a(11) =37017600a(12) =183879936a(13) =913398784a(14) =4537185280a(15) =22537856000a(16) =111953760256a(17) =556115206144