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 A152240 #20 Jan 19 2024 09:10:38
%S A152240 1,7,42,259,1589,9758,59913,367871,2258746,13868827,85155357,
%T A152240 522858574,3210380369,19711911863,121032221898,743144492531,
%U A152240 4562948015941,28016751527422,172024393748697,1056239229435439,6485366903418074
%N A152240 a(n)=5*a(n-1)+7*a(n-2), n>1 ; a(0)=1, a(1)=7 .
%C A152240 Unsigned version of A152239.
%H A152240 Paolo Xausa, <a href="/A152240/b152240.txt">Table of n, a(n) for n = 0..1000</a>
%H A152240 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (5,7).
%F A152240 G.f.: (1+2*x)/(1-5*x-7*x^2).
%t A152240 LinearRecurrence[{5, 7}, {1, 7}, 25] (* _Paolo Xausa_, Jan 19 2024 *)
%o A152240 (PARI) Vec((1+2*x)/(1-5*x-7*x^2)+O(x^99)) \\ _Charles R Greathouse IV_, Jan 17 2012
%Y A152240 Cf. A152187, A152224, A152239.
%K A152240 nonn,easy,less
%O A152240 0,2
%A A152240 _Philippe Deléham_, Nov 30 2008
%E A152240 Several terms corrected by _Johannes W. Meijer_, Aug 17 2010