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 A161587 #27 Oct 21 2024 02:36:00
%S A161587 1,24,73,148,249,376,529,708,913,1144,1401,1684,1993,2328,2689,3076,
%T A161587 3489,3928,4393,4884,5401,5944,6513,7108,7729,8376,9049,9748,10473,
%U A161587 11224,12001,12804,13633,14488,15369,16276,17209,18168,19153,20164
%N A161587 a(n) = 13*n^2 + 10*n + 1.
%C A161587 The defining formula can be regarded as an approximation and simplification of the expansion / propagation of native hydrophytes on the surface of stagnant waters in orthogonal directions; absence of competition / concurrence and of retrogression is assumed, mortality is taken into account. - [Translation of a comment in French sent by _Pierre Gayet_]
%H A161587 Pierre GAYET, <a href="/A161587/b161587.txt">Table of n, a(n) for n = 0..9999</a>
%H A161587 Pierre Gayet, <a href="/A162316/a162316.gif">Note et Compte rendu</a> (gif version).
%H A161587 Pierre Gayet, <a href="/A162316/a162316.pdf">Note et Compte Rendu</a> (pdf version).
%H A161587 Pierre Gayet, <a href="/A162316/a162316_1.txt">98 séquences générées ... par la formule générale indiquée</a>.
%H A161587 Claude Monet, <a href="http://lycees.ac-rouen.fr/bruyeres/jardin/Nymphea.html">Nymphéas</a>.
%H A161587 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A161587 a(n) = a(n-1) + 26*n - 3 (with a(0)=1). - _Vincenzo Librandi_, Nov 30 2010
%F A161587 From _Bruno Berselli_, Dec 12 2011: (Start)
%F A161587 G.f.: (1 + 21*x + 4*x^2)/(1-x)^3.
%F A161587 a(n-1) = A202141(n) - 1 with a(-1)=4. (End)
%F A161587 E.g.f.: exp(x)*(1 + 23*x + 13*x^2). - _Stefano Spezia_, Oct 21 2024
%t A161587 Table[13n^2+10n+1,{n,0,40}] (* or *) LinearRecurrence[{3,-3,1},{1,24,73},40] (* _Harvey P. Dale_, Nov 06 2014 *)
%o A161587 (Magma) [ 13*n^2+10*n+1: n in [0..50] ];
%o A161587 (PARI) a(n)=13*n^2+10*n+1 \\ _Charles R Greathouse IV_, Oct 07 2015
%Y A161587 Cf. A161532, A161549, A161617, A161935, A162316, A202141.
%K A161587 nonn,easy
%O A161587 0,2
%A A161587 _Pierre Gayet_, Jun 14 2009