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 A117807 #9 Jul 23 2015 14:39:58 %S A117807 1015,5105,5019,9109,9023,3213,3127,7217,7131,1321,1235,5325,5239, %T A117807 9329,9243,3433,3347,7437,7351,1541,1455,5545,5459,9549,9463,3653, %U A117807 3567,7657,7571,1761,1675,5765,5679,9769,9683,3873,3787,7877,7791,1981,1895,5985,5899,9989,9903,3103,3017,7107,7021,1211,1125,5215,5129,9219,9133,3323,3237,7327,7241,1431,1345,5435,5349,9439,9353,3543,3457,7547,7461,1651,1565,5655,5569,9659,9573,3763,3677,7767,7681,1871,1785,5875,5789,9879,9793,3983,3897,7987,7901,1101 %N A117807 Start with 1015 and repeatedly reverse the digits and add 4 to get the next term. %H A117807 N. J. A. Sloane and others, <a href="/wiki/Sequences_of_RADD_type">Sequences of RADD type</a>, OEIS wiki. %H A117807 <a href="/index/Rec#order_90">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, 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, 0, 1). %F A117807 Has period 90. A full period is shown. %t A117807 NestList[FromDigits[Reverse[IntegerDigits[#]]]+4&,1015,90] (* _Harvey P. Dale_, Jul 18 2015 *) %Y A117807 Cf. A117830, A117828. %K A117807 nonn,base %O A117807 1,1 %A A117807 _Klaus Brockhaus_, May 05 2006