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 A017042 #26 Aug 25 2024 18:48:40
%S A017042 25,144,361,676,1089,1600,2209,2916,3721,4624,5625,6724,7921,9216,
%T A017042 10609,12100,13689,15376,17161,19044,21025,23104,25281,27556,29929,
%U A017042 32400,34969,37636,40401,43264,46225,49284,52441,55696,59049,62500,66049,69696,73441,77284
%N A017042 a(n) = (7*n + 5)^2.
%H A017042 Vincenzo Librandi, <a href="/A017042/b017042.txt">Table of n, a(n) for n = 0..10000</a>
%H A017042 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A017042 G.f.: -(25 + 69*x + 4*x^2)/(x-1)^3. - _R. J. Mathar_, Jul 14 2016
%F A017042 Sum_{n>=0} 1/a(n) = psi'(5/7)/49 = 0.05601413956.. - _R. J. Mathar_, May 07 2024
%F A017042 E.g.f.: exp(x)*(25 + 119*x + 49*x^2). - _Stefano Spezia_, Aug 25 2024
%t A017042 (7*Range[0, 50] + 5)^2 (* _Paolo Xausa_, Aug 22 2024 *)
%o A017042 (Magma) [(7*n+5)^2: n in [0..40] ]; // _Vincenzo Librandi_, Jul 18 2011
%o A017042 (PARI) a(n)=(7*n+5)^2 \\ _Charles R Greathouse IV_, Feb 13 2017
%Y A017042 Cf. A000290, A017041.
%K A017042 nonn,easy
%O A017042 0,1
%A A017042 _N. J. A. Sloane_