Expansion of e.g.f.: 1/2 + exp(-4*x)/2.

Terms

a(0) =1a(1) =-2a(2) =8a(3) =-32a(4) =128a(5) =-512a(6) =2048a(7) =-8192a(8) =32768a(9) =-131072a(10) =524288a(11) =-2097152a(12) =8388608a(13) =-33554432a(14) =134217728a(15) =-536870912a(16) =2147483648a(17) =-8589934592a(18) =34359738368a(19) =-137438953472a(20) =549755813888