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 A089519 #4 Oct 09 2012 04:39:48 %S A089519 1,882,186876,28245672,3762380016,474431543712,58322293189056, %T A089519 7082435837377152,854925864902090496,102893307861680404992, %U A089519 12365333752840511118336,1484928368468173355231232 %N A089519 Fourth column (k=6) of array A078741 ((3,3)-Stirling2). %D A089519 P. Blasiak, K. A. Penson and A. I. Solomon, The general boson normal ordering problem, Phys. Lett. A 309 (2003) 198-205. %H A089519 P. Blasiak, K. A. Penson and A. I. Solomon, <a href="http://www.arXiv.org/abs/quant-ph/0402027">The general boson normal ordering problem.</a> %F A089519 G.f.: (1+672*x+14400*x^2)/((1-3*2*1*x)*(1-4*3*2*x)*(1-5*4*3*x)*(1-6*5*4*x)). %F A089519 a(n)= 20*(6*5*4)^n -30*(5*4*3)^n + 12*(4*3*2)^n - (3*2*1)^n = b(n) + 672*b(n-1) + 14400*b(n-2), with b(n) := A089514(n). %Y A089519 Cf. A089514, A089517-8, A090219. %K A089519 nonn,easy %O A089519 0,2 %A A089519 _Wolfdieter Lang_, Dec 01 2003