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 A192845 #22 Feb 16 2025 08:33:15
%S A192845 4,56,180,400,740,1224,1876,2720,3780,5080,6644,8496,10660,13160,
%T A192845 16020,19264,22916,27000,31540,36560,42084,48136,54740,61920,69700,
%U A192845 78104,87156,96880,107300,118440
%N A192845 Molecular topological indices of the sun graphs.
%C A192845 Sun graphs are defined for n >= 3; extended to n=1 using closed form.
%H A192845 G. C. Greubel, <a href="/A192845/b192845.txt">Table of n, a(n) for n = 1..1000</a>
%H A192845 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MolecularTopologicalIndex.html">Molecular Topological Index</a>
%H A192845 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).
%F A192845 a(n) = 4*n*(-3 + 3*n + n^2).
%F A192845 a(n) = 4*A090197(n).
%F A192845 G.f.: 4*x*(1 + 10*x - 5*x^2)/(1-x)^4. - _Colin Barker_, Aug 07 2012
%F A192845 E.g.f.: 4*x*(1 + 6*x + x^2)*exp(x). - _G. C. Greubel_, Jan 05 2019
%t A192845 Table[4*n*(-3+3*n+n^2), {n,1,40}] (* _G. C. Greubel_, Jan 05 2019 *)
%t A192845 LinearRecurrence[{4,-6,4,-1},{4,56,180,400},30] (* _Harvey P. Dale_, Mar 02 2024 *)
%o A192845 (PARI) vector(40, n, 4*n*(-3+3*n+n^2)) \\ _G. C. Greubel_, Jan 05 2019
%o A192845 (Magma) [4*n*(-3+3*n+n^2): n in [1..40]]; // _G. C. Greubel_, Jan 05 2019
%o A192845 (Sage) [4*n*(-3+3*n+n^2) for n in (1..40)] # _G. C. Greubel_, Jan 05 2019
%o A192845 (GAP) List([1..40], n -> 4*n*(-3+3*n+n^2)); # _G. C. Greubel_, Jan 05 2019
%Y A192845 Cf. A090197.
%K A192845 nonn,easy
%O A192845 1,1
%A A192845 _Eric W. Weisstein_, Jul 11 2011