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 A186339 #4 Mar 30 2012 18:59:28 %S A186339 1,4,32,512,32768,4194304,1073741824,1099511627776,2251799813685248, %T A186339 9223372036854775808,151115727451828646838272, %U A186339 4951760157141521099596496896,324518553658426726783156020576256,85070591730234615865843651857942052864 %N A186339 a(n)=A006125(n+1)*2^A001840(n). %C A186339 Hankel transform of A186338. %F A186339 a(n)=2^binomial(n+1,2)*2^floor((n+1)(n+2)/6). %K A186339 nonn,easy %O A186339 0,2 %A A186339 _Paul Barry_, Feb 18 2011