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 A004093 #25 Nov 14 2022 16:06:57 %S A004093 0,2,4,6,8,1,21,41,61,81,2,22,42,62,82,3,23,43,63,83,4,24,44,64,84,5, %T A004093 25,45,65,85,6,26,46,66,86,7,27,47,67,87,8,28,48,68,88,9,29,49,69,89, %U A004093 1,201,401,601,801,11,211,411,611,811,21,221,421,621,821,31 %N A004093 Even numbers written backwards. %H A004093 Reinhard Zumkeller, <a href="/A004093/b004093.txt">Table of n, a(n) for n = 0..10000</a> %F A004093 a(n) = A004086(2*n). - _Reinhard Zumkeller_, Feb 09 2012 %o A004093 (Haskell) %o A004093 a004093 = a004086 . (* 2) -- _Reinhard Zumkeller_, Feb 09 2012 %o A004093 (PARI) a(n) = fromdigits(Vecrev(digits(2*n))); \\ _Michel Marcus_, Nov 14 2022 %o A004093 (Python) %o A004093 def a(n): return int(str(2*n)[::-1]) %o A004093 print([a(n) for n in range(66)]) # _Michael S. Branicky_, Nov 14 2022 %Y A004093 Cf. A004086. %K A004093 nonn,base,look %O A004093 0,2 %A A004093 _N. J. A. Sloane_