This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A017990 #10 Sep 08 2022 08:44:44
%S A017990 1,2,3,5,9,15,25,43,74,125,214,366,625,1069,1828,3125,5344,9138,15625,
%T A017990 26719,45688,78125,133592,228439,390625,667960,1142195,1953125,
%U A017990 3339797,5710973,9765625,16698984,28554861,48828125,83494920,142774304,244140625
%N A017990 Powers of cube root of 5 rounded up.
%H A017990 Vincenzo Librandi, <a href="/A017990/b017990.txt">Table of n, a(n) for n = 0..200</a>
%t A017990 Table[Ceiling[5^(n/3)], {n, 0, 40}] (* _Vincenzo Librandi_, Jan 09 2014 *)
%o A017990 (Magma) [Ceiling(5^(n/3)): n in [0..50]]; // _Vincenzo Librandi_, Jan 09 2014
%Y A017990 Cf. powers of cube root of k ceiling up: A017981 (k=2), A017984 (k=3), A017987 (k=4), this sequence (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), A018035 (k=20), A018038 (k=21), A018041 (k=22), A018044 (k=23), A018047 (k=24).
%K A017990 nonn
%O A017990 0,2
%A A017990 _N. J. A. Sloane_
%E A017990 More terms from _Vincenzo Librandi_, Jan 09 2014