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 A140899 #13 Dec 12 2023 08:31:47 %S A140899 7,9,5,1,3,3,1,5,9,7,7,9,5,1,3,3,1,5,9,7,7,9,5,1,3,3,1,5,9,7,7,9,5,1, %T A140899 3,3,1,5,9,7 %N A140899 A140724(n+4). Period 10: repeat 7, 9, 5, 1, 3, 3, 1, 5, 9, 7. %C A140899 A140724= period 10: repeat 1, 5, 9, 7, 7, 9, 5, 1, 3, 3 . a(n) is one of its two palindromic decuplets. %H A140899 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (2,-2,2,-2,1). %F A140899 Note a(2n)+a(2n+1)= period 5: repeat 16, 6, 6, 6, 16 . %o A140899 (PARI) a(n)=[7, 9, 5, 1, 3, 3, 1, 5, 9, 7][n%10+1] \\ _Charles R Greathouse IV_, Jul 13 2016 %K A140899 nonn,easy %O A140899 0,1 %A A140899 _Paul Curtz_, Jul 24 2008