# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a156844 Showing 1-1 of 1 %I A156844 #20 Sep 08 2022 08:45:41 %S A156844 24335,469224,1473795,3038048,5161983,7845600,11088899,14891880, %T A156844 19254543,24176888,29658915,35700624,42302015,49463088,57183843, %U A156844 65464280,74304399,83704200,93663683,104182848,115261695,126900224 %N A156844 279841n^2 - 394634n + 139128. %C A156844 The identity (279841*n^2-394634*n+139128)^2-(529*n^2-746*n+263)*(12167*n-8579)^2=1 can be written as a(n)^2-A156842(n)*A156845(n)^2=1. %H A156844 Vincenzo Librandi, Table of n, a(n) for n = 1..10000 %H A156844 Index entries for linear recurrences with constant coefficients, signature (3,-3,1). %F A156844 a(n) = 3*a(n-1) -3*a(n-2) +a(n-3). %F A156844 G.f.: x*(-24335-396219*x-139128*x^2)/(x-1)^3. %t A156844 LinearRecurrence[{3,-3,1},{24335,469224,1473795},40] %t A156844 Table[279841n^2-394634n+139128,{n,30}] (* _Harvey P. Dale_, Mar 02 2021 *) %o A156844 (Magma) I:=[24335, 469224, 1473795]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..40]]; %o A156844 (PARI) a(n)=279841*n^2-394634*n+139128 \\ _Charles R Greathouse IV_, Dec 23 2011 %Y A156844 CF. A156842, A156845, A156849. %K A156844 nonn,easy %O A156844 1,1 %A A156844 _Vincenzo Librandi_, Feb 17 2009 %E A156844 Edited by _Charles R Greathouse IV_, Jul 25 2010 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE