Powers of sqrt(24) rounded down.

Terms

a(0) =1a(1) =4a(2) =24a(3) =117a(4) =576a(5) =2821a(6) =13824a(7) =67723a(8) =331776a(9) =1625363a(10) =7962624a(11) =39008731a(12) =191102976a(13) =936209559a(14) =4586471424a(15) =22469029417a(16) =110075314176a(17) =539256706015