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 A180497 #9 Jun 02 2025 03:04:16
%S A180497 1,1,6,4,13,9,1,16,6,25,13,36,22,4,33,13,46,24,61,37,9,52,22,69,37,1,
%T A180497 54,16,73,33,94,52,6,73,25,96,46,121,69,13,94,36,121,61,150,88,22,117,
%U A180497 49,148,78,4,109,33,142,64,177,97,13,132,46,169,81,208,118,24,157,61,198
%N A180497 a(n)=n^2-3*floor[n/sqrt(3)]^2.
%C A180497 a(n)=1 for n=A001075
%H A180497 Harvey P. Dale, <a href="/A180497/b180497.txt">Table of n, a(n) for n = 1..1000</a>
%e A180497 a(5)=13 since 5^2-3*floor[5/sqrt(3)]^2 =25-3*2^2=25-3*4=25-12=13
%t A180497 Table[n^2-3Floor[n/Sqrt[3]]^2,{n,70}] (* _Harvey P. Dale_, Nov 18 2024 *)
%Y A180497 Cf. A001075, A082532
%K A180497 nonn
%O A180497 1,3
%A A180497 _Carmine Suriano_, Sep 08 2010