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 A097856 #15 Oct 14 2014 04:23:25 %S A097856 0,1,3,5,15,17,21,51,63,65,85,195,255,257,273,325,341,771,819,975, %T A097856 1023,1025,1105,1285,1365,3075,3315,3855,4095,4097,4161,4369,4433, %U A097856 5125,5189,5397,5461,12291,12483,13107,13299,15375,15567,16191,16383,16385,16705 %N A097856 Base 10 numbers that are palindromic in bases 2 and 4. %C A097856 Intersection of A014192 and A006995. - _Michel Marcus_, Oct 11 2014 %H A097856 Robert G. Wilson v, <a href="/A097856/b097856.txt">Table of n, a(n) for n = 1..10000</a> %e A097856 255 base 2 = 11111111 and 255 base 4 = 3333. %Y A097856 Cf. A014192 (base 4), A006995 (base 2). %K A097856 base,nonn %O A097856 1,3 %A A097856 _Cino Hilliard_, Aug 31 2004