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 A157452 #6 Mar 30 2012 17:35:23
%S A157452 1,3,16,105,961,11137,160000,2738385,54479161,1234554321,31384248336,
%T A157452 884241045961,27342890695849,920521266133785,33512287502995456,
%U A157452 1311768467139281697,54933923639963082961,2450641333396432006369
%N A157452 Number generated by regarding the numbers in row n of A003983 as digits of a base n number.
%C A157452 We are regarding A003983 as a triangle, not as an array by antidiagonals.
%F A157452 t(n,m)=Min[1 + m, 1 + (n - m)]; a(n)=FromDigits[{Table[t[n, m], {m, 0, n}], n + 1}, n + 1].
%e A157452 Row 4 of A003983 is 1,2,2,1. The number 1221 in base 4 is 4^3 + 2*4^2 + 2*4 + 1 = 105, so a(4) = 105.
%t A157452 t[n_, m_] =Min[m, n - m + 1];
%t A157452 Table[FromDigits[{Table[t[n, m], {m, 1, n}], n}, n], {n, 1, 21}]
%Y A157452 A139038, A003983
%K A157452 nonn,base
%O A157452 1,2
%A A157452 _Roger L. Bagula_, Mar 01 2009
%E A157452 Edited by _Franklin T. Adams-Watters_, Sep 25 2011