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 A017987 #20 Jul 08 2025 06:21:06
%S A017987 1,2,3,4,7,11,16,26,41,64,102,162,256,407,646,1024,1626,2581,4096,
%T A017987 6502,10322,16384,26008,41286,65536,104032,165141,262144,416128,
%U A017987 660562,1048576,1664511,2642246,4194304,6658043,10568984,16777216,26632171,42275936,67108864
%N A017987 Powers of cube root of 4 rounded up.
%H A017987 Vincenzo Librandi, <a href="/A017987/b017987.txt">Table of n, a(n) for n = 0..200</a>
%H A017987 J. Peebles, <a href="http://www.math.hmc.edu/seniorthesis/archives/2013/jpeebles/jpeebles-2013-thesis-poster.pdf">Cap Set Bounds and Matrix Multiplication</a>, Math 197: Senior Thesis, Harvey Mudd College, 2013.
%t A017987 Ceiling[Surd[4,3]^Range[0,40]] (* _Harvey P. Dale_, May 15 2013 *)
%t A017987 Table[Ceiling[4^(n/3)], {n, 0, 40}] (* _Vincenzo Librandi_, Jan 09 2014 *)
%o A017987 (Magma) [Ceiling(4^(n/3)): n in [0..50]]; // _Vincenzo Librandi_, Jan 09 2014
%Y A017987 Cf. powers of cube root of k ceiling up: A017981 (k=2), A017984 (k=3), this sequence (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), A018035 (k=20), A018038 (k=21), A018041 (k=22), A018044 (k=23), A018047 (k=24).
%K A017987 nonn
%O A017987 0,2
%A A017987 _N. J. A. Sloane_
%E A017987 More terms from _Vincenzo Librandi_, Jan 09 2014