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 A098847 #48 Jan 15 2021 07:37:39
%S A098847 0,13,28,45,64,85,108,133,160,189,220,253,288,325,364,405,448,493,540,
%T A098847 589,640,693,748,805,864,925,988,1053,1120,1189,1260,1333,1408,1485,
%U A098847 1564,1645,1728,1813,1900,1989,2080,2173,2268,2365,2464,2565,2668,2773
%N A098847 a(n) = n*(n + 12).
%H A098847 G. C. Greubel, <a href="/A098847/b098847.txt">Table of n, a(n) for n = 0..1000</a>
%H A098847 Felix P. Muga II, <a href="https://www.researchgate.net/publication/267327689_Extending_the_Golden_Ratio_and_the_Binet-de_Moivre_Formula">Extending the Golden Ratio and the Binet-de Moivre Formula</a>, Preprint on ResearchGate, March 2014.
%H A098847 Wikipedia, <a href="http://en.wikipedia.org/wiki/Hydrogen_spectral_series">Hydrogen spectral series</a>, Humphreys series.
%H A098847 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A098847 a(n) = (n+6)^2 - 6^2 = n*(n + 12), n>=0.
%F A098847 G.f.: x*(13 - 11*x)/(1-x)^3.
%F A098847 a(n) = 2*n + a(n-1) + 11 (with a(0)=0). - _Vincenzo Librandi_, Nov 17 2010
%F A098847 a(0)=0, a(1)=13, a(2)=28, a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). - _Harvey P. Dale_, May 24 2012
%F A098847 Sum_{n>=1} 1/a(n) = 86021/332640 = 0.258600... via Sum_{n>=0} 1/((n+x)(n+y)) = (psi(x)-psi(y))/(x-y). - _R. J. Mathar_, Jul 14 2012
%F A098847 E.g.f.: x*(13 + x)*exp(x). - _G. C. Greubel_, Jul 29 2016
%F A098847 Sum_{n>=1} (-1)^(n+1)/a(n) = 18107/332640. - _Amiram Eldar_, Jan 15 2021
%t A098847 Table[ n(n + 12), {n, 0, 50}] (* _Robert G. Wilson v_, Jul 14 2005 *)
%t A098847 LinearRecurrence[{3,-3,1},{0,13,28},50] (* _Harvey P. Dale_, May 24 2012 *)
%o A098847 (PARI) a(n)=n*(n+12) \\ _Charles R Greathouse IV_, Sep 24 2015
%Y A098847 Cf. A098832, A063930.
%Y A098847 a(n-6), n>=7, sixth column (used for the n=6 series of the hydrogen atom) of triangle A120070.
%K A098847 nonn,easy
%O A098847 0,2
%A A098847 Eugene McDonnell (eemcd(AT)mac.com), Nov 04 2004
%E A098847 More terms from _Robert G. Wilson v_, Jul 14 2005