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 A090068 #9 Nov 30 2013 11:48:37 %S A090068 6,13,16,25,31,34,40,43,44,52,61,70,77,104,111,115,145,158,200,202, %T A090068 203,214,244,250,257,302,356,399,401,412,414,442,455,498,500,505,511, %U A090068 519,529,541,554,597,610,618,626,628,640,653,656,686,752,795,797,816,826 %N A090068 Numbers n such that there are (presumably) seven palindromes in the Reverse and Add! trajectory of n. %C A090068 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 A090068 <a href="/index/Res#RAA">Index entries for sequences related to Reverse and Add!</a> %e A090068 The trajectory of 25 begins 25, 77, 154, 605, 1111, 2222, 4444, 8888, 17776, 85547, 160105, 661166, 1322332, 3654563,7309126, ...; at 7309126 it joins the (presumably) palindrome-free trajectory of A063048(7) = 10577, hence 77, 1111, 2222, 4444, 8888, 661166 and 3654563 are the seven palindromes in the trajectory of 25 and 25 is a term. %Y A090068 Cf. A023108, A023109, A065001, A070742, A077594. %K A090068 nonn,base %O A090068 1,1 %A A090068 _Klaus Brockhaus_, Nov 20 2003