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 A120215 #19 Sep 21 2023 12:00:23 %S A120215 1057,7503,3059,9505,5061,1607,7063,3609,9065,5611,1167,7613,3169, %T A120215 9615,5171,1717,7173,3719,9175,5721,1277,7723,3279,9725,5281,1827, %U A120215 7283,3829,9285,5831,1387,7833,3389,9835,5391,1937,7393,3939,9395,5941,1497,7943,3499,9945,5501 %N A120215 Start with 1057 and repeatedly reverse the digits and add 2 to get the next term. %C A120215 Let T(S,Q) be the sequence obtained by starting with S and repeatedly reversing the digits and adding Q to get the next term. This is T(1057,2). 1057 is the first S for which T(S,2) reaches a cycle of length 45. The cycle is simply the first 45 terms, which then repeat. A full period is shown. %H A120215 N. J. A. Sloane and others, <a href="/wiki/Sequences_of_RADD_type">Sequences of RADD type</a>, OEIS wiki. %H A120215 <a href="/index/Rec#order_45">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1). %F A120215 a(n) = a(n-45). - _BoĊĦtjan Gec_, Sep 21 2023 %t A120215 NestList[IntegerReverse[#]+2&,1057,50] (* _Harvey P. Dale_, Jan 25 2021 *) %Y A120215 Cf. A117521, A118514, A120214, A120216, A120217, A120218. %K A120215 nonn,base %O A120215 1,1 %A A120215 _Klaus Brockhaus_, Jun 11 2006