Powers of cube root of 15 rounded up.

Terms

a(0) =1a(1) =3a(2) =7a(3) =15a(4) =37a(5) =92a(6) =225a(7) =555a(8) =1369a(9) =3375a(10) =8324a(11) =20528a(12) =50625a(13) =124852a(14) =307912a(15) =759375a(16) =1872780a(17) =4618673a(18) =11390625a(19) =28091697a(20) =69280083a(21) =170859375a(22) =421375454a(23) =1039201232a(24) =2562890625a(25) =6320631805a(26) =15588018474a(27) =38443359375a(28) =94809477069a(29) =233820277108