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

Terms

a(0) =1a(1) =5a(2) =25a(3) =121a(4) =589a(5) =2865a(6) =13937a(7) =67797a(8) =329801a(9) =1604329a(10) =7804317a(11) =37964385a(12) =184679137a(13) =898378405a(14) =4370194553a(15) =21258970969a(16) =103415040493a(17) =503066240401