a(n) = floor(a(n-1)*3/2) with a(1) = 5.

Terms

a(0) =5a(1) =7a(2) =10a(3) =15a(4) =22a(5) =33a(6) =49a(7) =73a(8) =109a(9) =163a(10) =244a(11) =366a(12) =549a(13) =823a(14) =1234a(15) =1851a(16) =2776a(17) =4164a(18) =6246a(19) =9369a(20) =14053a(21) =21079a(22) =31618a(23) =47427a(24) =71140a(25) =106710a(26) =160065a(27) =240097a(28) =360145a(29) =540217