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 A017925 #14 Sep 08 2022 08:44:43 %S A017925 1,2,7,18,49,129,343,907,2401,6352,16807,44467,117649,311269,823543, %T A017925 2178889,5764801,15252229,40353607,106765608,282475249,747359260, %U A017925 1977326743,5231514822,13841287201,36620603758 %N A017925 Powers of sqrt(7) rounded down. %H A017925 Vincenzo Librandi, <a href="/A017925/b017925.txt">Table of n, a(n) for n = 0..1000</a> %t A017925 Floor[(Sqrt[7])^Range[0,40]] (* _Vincenzo Librandi_, Nov 20 2011 *) %o A017925 (PARI) a(n)=sqrtint(7^n) \\ _Charles R Greathouse IV_, Nov 18 2011 %o A017925 (Magma) [Floor(Sqrt(7^n)): n in [0..40]]; // _Vincenzo Librandi_, Nov 20 2011 %K A017925 nonn %O A017925 0,2 %A A017925 _N. J. A. Sloane_