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 A257823 #10 Sep 08 2022 08:46:12 %S A257823 413,531,8673,11269,426511,554187,9192849,11944727,452101247, %T A257823 587437689,9744411267,12661399351,479226895309,622683396153, %U A257823 10329066750171,13421071367333,507980056926293,660043812484491,10948801010769993,14226322987973629,538458381114975271 %N A257823 Positive integers whose square is the sum of 59 consecutive squares. %C A257823 Positive integers x in the solutions to 2*x^2-118*y^2-6844*y-133458 = 0. %H A257823 Colin Barker, <a href="/A257823/b257823.txt">Table of n, a(n) for n = 1..1000</a> %H A257823 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,1060,0,0,0,-1). %F A257823 a(n) = 1060*a(n-4)-a(n-8). %F A257823 G.f.: -59*x*(x-1)*(7*x^6+16*x^5+163*x^4+354*x^3+163*x^2+16*x+7) / (x^8-1060*x^4+1). %e A257823 413 is in the sequence because 413^2 = 170569 = 22^2+23^2+...+80^2. %t A257823 LinearRecurrence[{0, 0, 0, 1060, 0, 0, 0, -1}, {413, 531, 8673, 11269, 426511, 554187, 9192849, 11944727}, 30] (* _Vincenzo Librandi_, May 11 2015 *) %o A257823 (PARI) Vec(-59*x*(x-1)*(7*x^6+16*x^5+163*x^4+354*x^3+163*x^2+16*x+7) / (x^8-1060*x^4+1) + O(x^100)) %o A257823 (Magma) I:=[413,531,8673,11269,426511,554187,9192849, 11944727]; [n le 8 select I[n] else 1060*Self(n-4)-Self(n-8): n in [1..30]]; // _Vincenzo Librandi_, May 11 2015 %Y A257823 Cf. A001653, A180274, A218395, A257761, A257765, A257767, A257780, A257781, A257824-A257828. %K A257823 nonn,easy %O A257823 1,1 %A A257823 _Colin Barker_, May 10 2015