Powers of fourth root of 2 rounded up.

Terms

a(0) =1a(1) =2a(2) =2a(3) =2a(4) =2a(5) =3a(6) =3a(7) =4a(8) =4a(9) =5a(10) =6a(11) =7a(12) =8a(13) =10a(14) =12a(15) =14a(16) =16a(17) =20a(18) =23a(19) =27a(20) =32a(21) =39a(22) =46a(23) =54a(24) =64a(25) =77a(26) =91a(27) =108a(28) =128a(29) =153