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 A262539 #6 Oct 04 2015 20:44:36
%S A262539 1,-3,9,-12,-99,1107,-7038,33345,-113643,151593,1547469,-17376120,
%T A262539 112734378,-544200660,1884830229,-2551628817,-26299018683,
%U A262539 298555990425,-1956243650733,9538198578972,-33464928293199,47571625958796,452674080810576,-5260288747038957,34841458485708282,-171603777320158968
%N A262539 a(n) = coefficient of x^n in the expansion of Product_{k>=1} (1-x^k)^(3*n).
%p A262539 C3:=proc(k) local t1,n;
%p A262539 t1:=mul((1-x^n)^(3*k),n=1..k+2);
%p A262539 series(t1,x,k+1);
%p A262539 coeff(%,x,k);
%p A262539 end;
%p A262539 [seq(C3(i),i=0..30)];
%Y A262539 Bisections: A262540, A262541.
%K A262539 sign
%O A262539 0,2
%A A262539 _N. J. A. Sloane_, Oct 04 2015