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 A117073 #15 Aug 02 2018 08:49:50
%S A117073 0,1,2,3,4,5,6,9,10,11,20,21,22,40,41,42,82,83,84,166,167,168,334,335,
%T A117073 336,670,671,672,1340,1341,1342,2682,2683,2684,5366,5367,5368,10734,
%U A117073 10735,10736,21470,21471,21472,42942,42943,42944,85886,85887,85888
%N A117073 Sequence of which A078783 is the Recamán transform.
%C A117073 The d() sequence mentioned in A078783. Absolute values of first differences of A078783.
%D A117073 N. J. A. Sloane and Allan Wilks, On sequences of Recaman type, paper in preparation, 2006.
%H A117073 Reinhard Zumkeller, <a href="/A117073/b117073.txt">Table of n, a(n) for n = 0..10000</a>
%t A117073 b[0] = 0; b[1] = 1;
%t A117073 b[n_] := b[n] = For[m = 2, True, m++, If[FreeQ[Array[b, n-1], m], If[Abs[m - b[n-1]] > Abs[b[n-1] - b[n-2]], Return[m]]]];
%t A117073 a[0] = 0; a[n_] := a[n] = Abs[b[n] - b[n-1]];
%t A117073 Table[Print["a(", n, ") = ", a[n]]; a[n], {n, 0, 50}] (* _Jean-François Alcover_, Aug 02 2018 *)
%o A117073 (Haskell)
%o A117073 a117073 n = a117073_list !! n
%o A117073 -- a117073_list defined in A078783. -- _Reinhard Zumkeller_, May 01 2015
%Y A117073 Cf. A078783.
%K A117073 nonn
%O A117073 0,3
%A A117073 _N. J. A. Sloane_, Apr 17 2006