Powers of sqrt(6) rounded down.

Terms

a(0) =1a(1) =2a(2) =6a(3) =14a(4) =36a(5) =88a(6) =216a(7) =529a(8) =1296a(9) =3174a(10) =7776a(11) =19047a(12) =46656a(13) =114283a(14) =279936a(15) =685700a(16) =1679616a(17) =4114202a(18) =10077696a(19) =24685212a(20) =60466176a(21) =148111277a(22) =362797056a(23) =888667667a(24) =2176782336a(25) =5332006004a(26) =13060694016