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 A157455 #6 Mar 30 2012 17:35:23
%S A157455 1,3,19,125,1141,12943,182743,3080025,60530761,1357997531,34237329611,
%T A157455 957927505717,29446189175677,986272776455415,35746439978786671,
%U A157455 1393753996031259953,58165330912030118161,2586788074128361802419
%N A157455 Number generated by regarding the numbers in row n of A157454 as digits of a base n number.
%C A157455 Note that for odd n, the digits will include n itself.
%F A157455 t(n,m)=Min[2*m - 1, 2*(n - m) + 1]; a(n)=FromDigits[{Table[t[n, m], {m, 1, n}], n}, n].
%e A157455 Row 4 of A157454 is 1,3,3,1. 1331 in base 4 = 4^3 + 3*4^2 + 3*4 + 1 = 125, so a(4) = 125.
%t A157455 t[n_, m_] =Min[1 + 2*m, 1 + 2*(n - m)];
%t A157455 Table[FromDigits[{Table[t[n, m], {m, 0, n}], n + 1}, n + 1], {n, 0, 20}]
%Y A157455 A139038, A003983
%K A157455 nonn,base
%O A157455 1,2
%A A157455 _Roger L. Bagula_, Mar 01 2009
%E A157455 Edited by _Franklin T. Adams-Watters_, Sep 25 2011