Powers of sqrt(19) rounded up.

Terms

a(0) =1a(1) =5a(2) =19a(3) =83a(4) =361a(5) =1574a(6) =6859a(7) =29898a(8) =130321a(9) =568057a(10) =2476099a(11) =10793066a(12) =47045881a(13) =205068241a(14) =893871739a(15) =3896296579a(16) =16983563041a(17) =74029634997a(18) =322687697779