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 A276854 #19 Mar 24 2021 15:35:58
%S A276854 0,3,6,9,12,16,19,22,25,29,32,35,38,42,45,48,51,55,58,61,64,67,71,74,
%T A276854 77,80,84,87,90,93,97,100,103,106,110,113,116,119,122,126,129,132,135,
%U A276854 139,142,145,148,152,155,158,161,165,168,171,174,177,181,184,187
%N A276854 Beatty sequence for 1 + sqrt(5).
%C A276854 A bisection of the lower Wythoff sequence, A000201.
%H A276854 Clark Kimberling, <a href="/A276854/b276854.txt">Table of n, a(n) for n = 0..10000</a>
%H A276854 N. J. A. Sloane, <a href="/A115004/a115004.txt">Families of Essentially Identical Sequences</a>, Mar 24 2021 (Includes this sequence)
%F A276854 a(n) = floor(n*(1 + sqrt(5))).
%t A276854 z = 500; r = 1+Sqrt[5]; b = Table[Floor[k*r], {k, 0, z}] (* A276854 *)
%o A276854 (Python)
%o A276854 from sympy import integer_nthroot
%o A276854 def A276854(n): return n+integer_nthroot(5*n**2,2)[0] # _Chai Wah Wu_, Mar 16 2021
%Y A276854 Cf. A022839, A276863, A276881.
%K A276854 nonn,easy
%O A276854 0,2
%A A276854 _Clark Kimberling_, Sep 24 2016