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 A090063 #9 Nov 30 2013 11:47:39 %S A090063 49,58,67,76,85,94,108,118,127,133,143,148,153,173,177,178,198,207, %T A090063 217,226,239,247,276,277,279,297,306,316,325,331,338,339,341,346,349, %U A090063 351,371,375,376,378,379,396,405,415,419,430,437,438,440,445,448,450,464 %N A090063 Numbers n such that there are (presumably) two palindromes in the Reverse and Add! trajectory of n. %C A090063 For terms < 2000 each palindrome is reached from the preceding one or from the start in at most 24 steps; after the presumably last one no further palindrome is reached in 2000 steps. %H A090063 <a href="/index/Res#RAA">Index entries for sequences related to Reverse and Add!</a> %e A090063 The trajectory of 118 begins 118, 929, 1858, 10439, 103840, 152141, 293392, 586784, 1074469, ...; at 1074469 it joins the (presumably) palindrome-free trajectory of A063048(72) = 90379, hence 929 and 293392 are the two palindromes in the trajectory of 118 and 118 is a term. %Y A090063 Cf. A023108, A023109, A065001, A070742, A077594. %K A090063 nonn,base %O A090063 1,1 %A A090063 _Klaus Brockhaus_, Nov 20 2003