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 A259390 #8 Aug 18 2015 12:57:29
%S A259390 0,1,2,3,4,5,6,8,40,50,100,164,200,264,300,328,400,2000,3550,8200,
%T A259390 10252,14510,14762,22800,45600,164900,201720,400200,532900,555013,
%U A259390 738100,2756120,2913368,3344352,3501600,4084000,12990350,22674550,194062432,1684866370,2225211080,13575144288,15127811455,20404027400,20537111057,22668403353,30862471355,83714515310,84668107250,796259955485,1202029647736,2088800185930,20268849562000
%N A259390 Palindromic numbers in bases 7 and 9 written in base 10.
%H A259390 Giovanni Resta, <a href="/A259390/b259390.txt">Table of n, a(n) for n = 1..86</a>
%H A259390 <a href="/index/Pac#palindromes">Index entries for sequences related to palindromes</a>
%F A259390 Intersection of A029954 and A029955.
%e A259390 264 is in the sequence because 264_10 = 323_9 = 525_7.
%t A259390 (* first load nthPalindromeBase from A002113 *) palQ[n_Integer, base_Integer] := Block[{}, Reverse[ idn = IntegerDigits[n, base]] == idn]; k = 0; lst = {}; While[k < 21000000, pp = nthPalindromeBase[k, 9]; If[palQ[pp, 7], AppendTo[lst, pp]; Print[pp]]; k++]; lst
%Y A259390 Cf. A048268, A060792, A097856, A097928, A182232, A259374, A097929, A182233, A259375, A259376,
%Y A259390 A097930, A182234, A259377, A259378, A249156, A097931, A259380, A259381, A259382, A259383,
%Y A259390 A259384, A099145, A259385, A259386, A259387, A259388, A259389, A259390, A099146, A007632,
%Y A259390 A007633, A029961, A029962, A029963, A029964, A029804, A029965, A029966, A029967, A029968,
%Y A259390 A029969, A029970, A029731, A097855, A250408, A250409, A250410, A250411, A099165, A250412.
%K A259390 nonn,base
%O A259390 1,3
%A A259390 Eric A. Schmidt and _Robert G. Wilson v_, Jul 17 2015