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 A255606 #19 Aug 25 2025 19:24:45
%S A255606 2,10,23,41,64,93,127,166,210,259,314,374,439,509,584,665,750,841,937,
%T A255606 1039,1145,1257,1374,1496,1623,1756,1893,2036,2184,2338,2496,2660,
%U A255606 2829,3003,3182,3367,3556,3751,3951,4156,4367,4583,4803,5029,5261,5497,5739,5985,6237,6495
%N A255606 Integer part of the area of a hexagon with side length n.
%C A255606 Column 4 of A255604.
%H A255606 Harvey P. Dale, <a href="/A255606/b255606.txt">Table of n, a(n) for n = 1..1000</a>
%F A255606 a(n) = floor(6*n^2/(4*tan(Pi/6))), n >= 1.
%t A255606 Table[IntegerPart[(6*n^2/(4*Tan[Pi/6]))], {n, 50}] (* _Michael De Vlieger_, Mar 18 2015 *)
%t A255606 Floor[3/2 Sqrt[3] Range[50]^2] (* _Harvey P. Dale_, Aug 25 2025 *)
%o A255606 (PARI){for(n=1,100,a=floor(6*n^2/(4*tan(Pi/6)));print1(a,", "))}
%o A255606 (PARI) a(n) = sqrtint(27*n^4)>>1; \\ _Kevin Ryde_, May 07 2021
%Y A255606 Cf. A104956, A255604.
%K A255606 nonn,changed
%O A255606 1,1
%A A255606 _Kival Ngaokrajang_, Feb 27 2015