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 A033444 #30 Feb 16 2025 08:32:36
%S A033444 0,0,1,3,6,10,15,21,28,36,45,55,66,77,89,102,116,131,147,164,182,201,
%T A033444 221,242,264,286,309,333,358,384,411,439,468,498,529,561,594,627,661,
%U A033444 696,732,769,807,846,886,927,969,1012,1056,1100,1145,1191,1238,1286
%N A033444 Number of edges in 12-partite Turán graph of order n.
%D A033444 Graham et al., Handbook of Combinatorics, Vol. 2, p. 1234.
%H A033444 Vincenzo Librandi, <a href="/A033444/b033444.txt">Table of n, a(n) for n = 0..1000</a>
%H A033444 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TuranGraph.html">Turán Graph</a> [_Reinhard Zumkeller_, Nov 30 2009]
%H A033444 Wikipedia, <a href="http://en.wikipedia.org/wiki/Tur%C3%A1n_graph">Turán graph</a> [_Reinhard Zumkeller_, Nov 30 2009]
%H A033444 <a href="/index/Rec#order_14">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1,0,0,0,0,0,0,0,0,0,1,-2,1).
%F A033444 a(n) = Sum_{k=0..n} A168185(k)*(n-k). [_Reinhard Zumkeller_, Nov 30 2009]
%F A033444 G.f.: -x^2*(x^10+x^9+x^8+x^7+x^6+x^5+x^4+x^3+x^2+x+1)/((x-1)^3*(x+1)*(x^2-x+1)*(x^2+1)*(x^2+x+1)*(x^4-x^2+1)). [_Colin Barker_, Aug 09 2012]
%F A033444 a(n) = Sum_{i=1..n} floor(11*i/12). - _Wesley Ivan Hurt_, Sep 12 2017
%t A033444 CoefficientList[Series[- x^2 (x^10 + x^9 + x^8 + x^7 + x^6 + x^5 + x^4 + x^3 + x^2 + x + 1)/((x - 1)^3 (x + 1) (x^2 - x + 1) (x^2 + 1) (x^2 + x + 1) (x^4 - x^2 + 1)), {x, 0, 60}], x] (* _Vincenzo Librandi_, Oct 20 2013 *)
%Y A033444 Cf. A002620, A000212, A033436, A033437, A033438, A033439, A033440, A033441, A033442, A033443. [_Reinhard Zumkeller_, Nov 30 2009]
%K A033444 nonn,easy
%O A033444 0,4
%A A033444 _N. J. A. Sloane_
%E A033444 More terms from _Vincenzo Librandi_, Oct 20 2013