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 A017926 #14 Sep 08 2022 08:44:43 %S A017926 1,3,7,19,49,130,343,907,2401,6352,16807,44467,117649,311270,823543, %T A017926 2178890,5764801,15252230,40353607,106765609,282475249,747359260, %U A017926 1977326743,5231514823,13841287201,36620603759 %N A017926 Powers of sqrt(7) rounded to nearest integer. %H A017926 Vincenzo Librandi, <a href="/A017926/b017926.txt">Table of n, a(n) for n = 0..2000</a> %t A017926 Floor[(Sqrt[7]^Range[0,40]+1/2)] (* _Vincenzo Librandi_, Nov 19 2011 *) %o A017926 (PARI) a(n)=round(sqrt(7)^n) \\ _Charles R Greathouse IV_, Nov 18 2011 %o A017926 (Magma) [Round(Sqrt(7)^n): n in [0..40]]; // _Vincenzo Librandi_, Nov 19 2011 %K A017926 nonn %O A017926 0,2 %A A017926 _N. J. A. Sloane_