%I #15 Feb 12 2023 17:42:02
%S 1,3,8,20,55,148,400,1086,2948,8000,21716,58945,160000,434307,1178891,
%T 3200000,8686137,23577802,64000000,173722728,471556032,1280000000,
%U 3474454550,9431120637,25600000000,69489090985,188622412731,512000000000,1389781819697
%N Powers of cube root of 20 rounded up.
%H Vincenzo Librandi, <a href="/A018035/b018035.txt">Table of n, a(n) for n = 0..200</a>
%t With[{c=20^(1/3)}, Ceiling[c^Range[0, 30]]] (* _Harvey P. Dale_, Apr 07 2012 *)
%t Table[Ceiling[20^(n/3)], {n, 0, 40}] (* _Vincenzo Librandi_, Jan 10 2014 *)
%t Ceiling[CubeRoot[20]^Range[0,40]] (* _Harvey P. Dale_, Feb 12 2023 *)
%o (Magma) [Ceiling(20^(n/3)): n in [0..40]]; // _Vincenzo Librandi_, Jan 10 2014
%Y Cf. powers of cube root of k ceiling up: A017981 (k=2), A017984 (k=3), A017987 (k=4), A017990 (k=5), A017993 (k=6), A017996 (k=7), A018002 (k=9), A018005 (k=10), A018008 (k=11), A018011 (k=12), A018014 (k=13), A018017 (k=14), A018020 (k=15), A018023 (k=16), A018026 (k=17), A018029 (k=18), A018032 (k=19), this sequence (k=20), A018038 (k=21), A018041 (k=22), A018044 (k=23), A018047 (k=24).
%K nonn
%O 0,2
%A _N. J. A. Sloane_
%E More terms from _Vincenzo Librandi_, Jan 10 2014