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 A077407 #17 Feb 26 2019 11:00:12 %S A077407 0,1,2,3,4,18,20,21,27,28,55,56,57,70 %N A077407 In base 3, records for the number of Reverse and Add! steps needed to reach a palindrome. %C A077407 RECORDS transform of A077402. Base-3 analog of A066145 (base 2), A075687 (base 4) and A065199 (base 10). A077406 gives the corresponding starting points. %C A077407 Probable Lychrel numbers are ignored, the first of which is 103. - _Sean A. Irvine_, Apr 19 2010 %H A077407 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a> %H A077407 <a href="/index/Res#RAA">Index entries for sequences related to Reverse and Add!</a> %e A077407 Starting with 15, 3 Reverse and Add! steps are needed to reach a palindrome; starting with n < 15, less (at most 2) steps are needed. %Y A077407 Cf. A065199, A066145, A075687, A077402, A077406. %K A077407 base,more,nonn %O A077407 1,3 %A A077407 _Klaus Brockhaus_, Nov 05 2002 %E A077407 a(14) from _Sean A. Irvine_, Apr 19 2010