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 A216907 #16 Aug 22 2015 00:49:52 %S A216907 318713056300,101252880671531,778061547945037,8047782883062742, %T A216907 37866346844745025,247644110790746909,828823170233185174, %U A216907 10556938000726441969,10175119610486126649,34575397981277771773,91506808775956056797 %N A216907 Smallest palindromic number of length 13 in two bases differing by n. %C A216907 See comments sections of A216840 and A216841. Smallest of pair of bases are 8, 12, 14, 17, 19, 22, 24, 30, 32. For the remarkable case a(10), not only does the number have four 7s in a row in base 10, but it also has prime reversal there and in its 2nd base of 13-palindromicity, 42, no digit larger than 20 appears. A216*** cross-references are others in a collection of sequences that includes this one, while A171*** ones are various record multi-base palindromes. %e A216907 The first term is 4506461646054 in base 8 and 1113578753111 in base 9. %Y A216907 Cf. A171701, A171702, A171703, A171704, A171705, A171706, A171740, A171741, A171742, A171775, A216840, A216841, A216843, A216899, A216900, A216901, A216902, A216903, A216904, A216905, A216906, A216908, A216909, A216910. %K A216907 nonn,base %O A216907 1,1 %A A216907 _James G. Merickel_, Sep 19 2012 %E A216907 a(10) added by _James G. Merickel_, Oct 17 2012 %E A216907 a(11) from _Chai Wah Wu_, Aug 20 2015