Recip transform of 2*(1 + x^3 + x^6)-1/(1-x).

Terms

a(0) =1a(1) =1a(2) =3a(3) =9a(4) =33a(5) =127a(6) =517a(7) =2173a(8) =9379a(9) =41295a(10) =184789a(11) =837903a(12) =3841603a(13) =17778605a(14) =82941987a(15) =389655675a(16) =1841797725a(17) =8752809573a(18) =41796432863a(19) =200446855069a(20) =965032948861