E.g.f. exp(x)*BesselI(2,2*sqrt(3)*x)/3.

Terms

a(0) =0a(1) =0a(2) =1a(3) =3a(4) =18a(5) =70a(6) =330a(7) =1386a(8) =6160a(9) =26496a(10) =115965a(11) =502975a(12) =2194302a(13) =9553050a(14) =41687737a(15) =181908195a(16) =794770200a(17) =3474159304a(18) =15199740171a(19) =66541189473a(20) =291507681070