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 A102083 #36 Jul 15 2017 02:05:21
%S A102083 1,13,41,85,145,221,313,421,545,685,841,1013,1201,1405,1625,1861,2113,
%T A102083 2381,2665,2965,3281,3613,3961,4325,4705,5101,5513,5941,6385,6845,
%U A102083 7321,7813,8321,8845,9385,9941,10513,11101,11705,12325,12961,13613,14281,14965,15665
%N A102083 a(n) = 8*n^2 + 4*n + 1.
%C A102083 If Y and Z are 2-blocks of a 2n-set X then, for n>=2, a(n-2) is the number of 4-subsets of X intersecting both Y and Z. - _Milan Janjic_, Nov 18 2007
%C A102083 Equals binomial transform of [1, 12, 16, 0, 0, 0, ...]. - _Gary W. Adamson_, Jul 19 2008
%C A102083 Sequence found by reading the line from 1, in the direction 1, 13, ..., in the square spiral whose vertices are the triangular numbers A000217. - _Omar E. Pol_, Sep 05 2011
%C A102083 First differences of A100157. - _John Molokach_, Jul 10 2013
%H A102083 G. C. Greubel, <a href="/A102083/b102083.txt">Table of n, a(n) for n = 0..5000</a>
%H A102083 Milan Janjic, <a href="http://www.pmfbl.org/janjic/">Two Enumerative Functions</a>
%H A102083 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A102083 G.f.: (1+10*x+5*x^2)/(1-x)^3. - _Paul Barry_, Jun 04 2005
%F A102083 a(n) = 4*(4*n-1)+a(n-1) (with a(0)=1). - _Vincenzo Librandi_, Nov 16 2010
%F A102083 E.g.f.: (8*x^2 + 12*x + 1)*exp(x). - _G. C. Greubel_, Jul 14 2017
%t A102083 Table[8*n^2 + 4*n + 1, {n, 0, 300}] (* or *) LinearRecurrence[{3, -3, 1}, {1, 13, 41}, 80] (* _Vladimir Joseph Stephan Orlovsky_, Feb 17 2012 *)
%o A102083 (PARI) a(n)=8*n^2+4*n+1 \\ _Charles R Greathouse IV_, Oct 07 2015
%Y A102083 Cf. A085601, A195241.
%K A102083 nonn,easy
%O A102083 0,2
%A A102083 _N. J. A. Sloane_, Feb 14 2005