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 A083692 #5 Mar 30 2012 18:37:43
%S A083692 1,3,10,38,148,620,2600,11480,50256,229296,1032352,4816736,22118720,
%T A083692 104890048,488768128,2346515840,11058545920,53605825280,254908828160,
%U A083692 1245304583680,5965139153920,29328419056640,141339991746560
%N A083692 Length of list generated by n replacements of k by {-1-|k|, .., 1+|k|} with increment 2, starting with {1}.
%C A083692 Same sequence starting with {0}: see A083691. Sum of absolute values of list elements gives A083693. Cross-references cite sequences with similar generation by integer-substitution and length of resulting lists.
%F A083692 Drop first 2 terms from A083691 and divide by 2.
%e A083692 0, 1 and 2 substitutions produce lengths 1, 3 and 10:
%e A083692 {1}; {-2,0,2}; {-3,-1,1,3, -1,1, -3,-1,1,3}
%t A083692 Table[Length@Flatten[Nest[ #/.k_Integer:>Table[i, {i, -1-Abs[k], Abs[k]+1, 2}]&, {1}, w]], {w, 0, 10}]
%Y A083692 Cf. A000108, A001003, A006319.
%K A083692 nonn
%O A083692 0,2
%A A083692 _Wouter Meeussen_, May 03 2003