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 A152401 #4 Mar 30 2012 18:37:15 %S A152401 1,2,8,45,318,2671,25805,280609,3381993,44658052,640279918,9895457035, %T A152401 163871617543,2893296199441,54230087607409,1075060346670798, %U A152401 22467666780553040,493590689966427930,11369641989418301977 %N A152401 Column 1 of triangle A152400; also, column 1 of square array A152405. %C A152401 Matrix powers of triangle T=A152400 satisfy: column k of T^(j+1) = column j of T^(k+1) for all j>=0, k>=0. %H A152401 Paul D. Hanna, <a href="/A152401/b152401.txt">Table of n, a(n), n=0..100.</a> %Y A152401 Cf. A152400; A127715, A152402, A152403, A152404; A152405. %K A152401 nonn %O A152401 0,2 %A A152401 _Paul D. Hanna_, Dec 05 2008