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 A017994 #13 Sep 08 2022 08:44:44
%S A017994 1,1,3,7,13,25,49,93,179,343,656,1255,2401,4592,8785,16807,32150,
%T A017994 61501,117649,225054,430513,823543,1575381,3013595,5764801,11027667,
%U A017994 21095169,40353607,77193673,147666184,282475249,540355712,1033663291,1977326743,3782489985
%N A017994 Powers of cube root of 7 rounded down.
%H A017994 Vincenzo Librandi, <a href="/A017994/b017994.txt">Table of n, a(n) for n = 0..200</a>
%t A017994 Table[Floor[7^(n/3)], {n, 0, 40}] (* _Vincenzo Librandi_, Jan 06 2014 *)
%t A017994 Floor[Surd[7,3]^Range[0,40]] (* _Harvey P. Dale_, Apr 05 2019 *)
%o A017994 (Magma) [Floor(7^(n/3)): n in [0..50]]; // _Vincenzo Librandi_, Jan 06 2014
%Y A017994 Cf. powers of cube root of k rounded down: A017979 (k=2), A017982 (k=3), A017985 (k=4), A017988 (k=5), A017991 (k=6), this sequence (k=7), A018000 (k=9), A018003 (k=10), A018006 (k=11), A018009 (k=12), A018012 (k=13), A018015 (k=14), A018018 (k=15), A018021 (k=16), A018024 (k=17), A018027 (k=18), A018030 (k=19), A018033 (k=20), A018036 (k=21), A018039 (k=22), A018042 (k=23), A018045 (k=24).
%K A017994 nonn
%O A017994 0,3
%A A017994 _N. J. A. Sloane_
%E A017994 More terms from _Vincenzo Librandi_, Jan 06 2014