Powers of sqrt(6) rounded up.

Terms

a(0) =1a(1) =3a(2) =6a(3) =15a(4) =36a(5) =89a(6) =216a(7) =530a(8) =1296a(9) =3175a(10) =7776a(11) =19048a(12) =46656a(13) =114284a(14) =279936a(15) =685701a(16) =1679616a(17) =4114203a(18) =10077696a(19) =24685213a(20) =60466176a(21) =148111278a(22) =362797056a(23) =888667668a(24) =2176782336a(25) =5332006005a(26) =13060694016