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 A257824 #10 Sep 08 2022 08:46:12 %S A257824 4088,23360,1582640,9047912,18642443912,106578370640,7220791811360, %T A257824 41281080400088,85056113063608088,486263602888235360, %U A257824 32944848197744794640,188344846763231651912,388068345740467131839912,2218576715650261475158640,150310804012507009263599360 %N A257824 Positive integers whose square is the sum of 73 consecutive squares. %C A257824 Positive integers x in the solutions to 2*x^2-146*y^2-10512*y-254040 = 0. %H A257824 Colin Barker, <a href="/A257824/b257824.txt">Table of n, a(n) for n = 1..600</a> %H A257824 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,4562498,0,0,0,-1). %F A257824 a(n) = 4562498*a(n-4)-a(n-8). %F A257824 G.f.: -584*x*(x-1)*(7*x^6+47*x^5+2757*x^4+18250*x^3+2757*x^2+47*x+7) / ((x^4-2136*x^2-1)*(x^4+2136*x^2-1)). %e A257824 4088 is in the sequence because 4088^2 = 16711744 = 442^2+443^2+...+514^2. %t A257824 LinearRecurrence[{0, 0, 0, 4562498, 0, 0, 0, -1}, {4088, 23360, 1582640, 9047912, 18642443912, 106578370640, 7220791811360, 41281080400088}, 40] (* _Vincenzo Librandi_, May 11 2015 *) %o A257824 (PARI) Vec(-584*x*(x-1)*(7*x^6+47*x^5+2757*x^4+18250*x^3+2757*x^2+47*x+7) / ((x^4-2136*x^2-1)*(x^4+2136*x^2-1)) + O(x^100)) %o A257824 (Magma) I:=[4088,23360,1582640,9047912,18642443912, 106578370640,7220791811360,41281080400088]; [n le 8 select I[n] else 4562498*Self(n-4)-Self(n-8): n in [1..20]]; // _Vincenzo Librandi_, May 11 2015 %Y A257824 Cf. A001653, A180274, A218395, A257761, A257765, A257767, A257780, A257781, A257823, A257825-A257828. %K A257824 nonn,easy %O A257824 1,1 %A A257824 _Colin Barker_, May 10 2015