Expansion of e.g.f. BesselI(0,4*x)+BesselI(1,4*x)/2.

Terms

a(0) =1a(1) =1a(2) =8a(3) =12a(4) =96a(5) =160a(6) =1280a(7) =2240a(8) =17920a(9) =32256a(10) =258048a(11) =473088a(12) =3784704a(13) =7028736a(14) =56229888a(15) =105431040a(16) =843448320a(17) =1593180160a(18) =12745441280a(19) =24216338432a(20) =193730707456a(21) =369849532416