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 A168547 #15 May 21 2023 12:05:17
%S A168547 1,3,17,59,145,291,513,827,1249,1795,2481,3323,4337,5539,6945,8571,
%T A168547 10433,12547,14929,17595,20561,23843,27457,31419,35745,40451,45553,
%U A168547 51067,57009,63395,70241,77563,85377,93699,102545,111931,121873,132387,143489,155195
%N A168547 a(n) = 1 - 2*n^2 + 4*n*(1 + 2*n^2)/3.
%C A168547 Binomial transform of the quasi-finite sequence 1,2,12,16,0,... (0 continued).
%C A168547 A bisection of A168582.
%H A168547 Vincenzo Librandi, <a href="/A168547/b168547.txt">Table of n, a(n) for n = 0..10000</a>
%H A168547 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).
%F A168547 a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).
%F A168547 G.f.: (1 - x + 11*x^2 + 5*x^3)/(x-1)^4.
%F A168547 First differences: a(n+1) - a(n) = 2*A054569(n+1).
%F A168547 Second differences: a(n+2) - 2*a(n+1) + a(n) = 4*A004767(n).
%F A168547 Third differences: a(n+3) - 3*a(n+2) + 3*a(n+1) - a(n) = 16.
%F A168547 a(n+1) = A166464(n) + A035597(n+1).
%F A168547 a(n) = 1 - 2*n^2 + 4*A005900(n). - _R. J. Mathar_, Dec 05 2009
%F A168547 E.g.f.: (1/3)*(3 + 6*x + 18*x^2 + 8*x^3)*exp(x). - _G. C. Greubel_, Jul 26 2016
%t A168547 Table[1-2*n^2+4*n*(1+2*n^2)/3, {n,0,50}] (* _G. C. Greubel_, Jul 26 2016 *)
%t A168547 LinearRecurrence[{4,-6,4,-1},{1,3,17,59},60] (* _Harvey P. Dale_, May 21 2023 *)
%o A168547 (Magma) [1-2*n^2+4*n*(1+2*n^2)/3: n in [0..50] ]; // _Vincenzo Librandi_, Aug 06 2011
%o A168547 (PARI) a(n)=1-2*n^2+4*n*(1+2*n^2)/3 \\ _Charles R Greathouse IV_, Jul 26 2016
%K A168547 nonn,easy
%O A168547 0,2
%A A168547 _Paul Curtz_, Nov 29 2009
%E A168547 Edited and extended by _R. J. Mathar_, Dec 05 2009