a(0) = 1; thereafter a(n) = floor((9/4)*a(n-1)) + 1.

Terms

a(0) =1a(1) =3a(2) =7a(3) =16a(4) =37a(5) =84a(6) =190a(7) =428a(8) =964a(9) =2170a(10) =4883a(11) =10987a(12) =24721a(13) =55623a(14) =125152a(15) =281593a(16) =633585a(17) =1425567a(18) =3207526a(19) =7216934a(20) =16238102a(21) =36535730a(22) =82205393a(23) =184962135a(24) =416164804a(25) =936370810a(26) =2106834323a(27) =4740377227a(28) =10665848761a(29) =23998159713