a(n) = 19683*n - 5967.

Terms

a(0) =13716a(1) =33399a(2) =53082a(3) =72765a(4) =92448a(5) =112131a(6) =131814a(7) =151497a(8) =171180a(9) =190863a(10) =210546a(11) =230229a(12) =249912a(13) =269595a(14) =289278a(15) =308961a(16) =328644a(17) =348327a(18) =368010a(19) =387693a(20) =407376a(21) =427059a(22) =446742a(23) =466425a(24) =486108a(25) =505791a(26) =525474a(27) =545157a(28) =564840a(29) =584523