a(n) = floor(tau*a(n-1)) + floor(tau*a(n-2)) with a(0)=1 and a(1)=3.

Terms

a(0) =1a(1) =3a(2) =5a(3) =12a(4) =27a(5) =62a(6) =143a(7) =331a(8) =766a(9) =1774a(10) =4109a(11) =9518a(12) =22048a(13) =51074a(14) =118313a(15) =274073a(16) =634893a(17) =1470737a(18) =3406980a(19) =7892311a(20) =18282636a(21) =42351953a(22) =98108825a(23) =227270312a(24) =526474502a(25) =1219584727a(26) =2825183178a(27) =6544571946a(28) =15160582256a(29) =35119677229