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 A077272 #6 May 10 2013 12:45:07
%S A077272 0,0,1,2,11,4,57,6,159,80,441,10,1567,12,3197,958,8647,16,23301,18,
%T A077272 53003,6508,124005,22,315755,1624,692345,41786,1615939,28,3795873,30,
%U A077272 8414231,248200,18940065,14978,43126711,36,94634165,1384918,209905711,40,465656541
%N A077272 a(n) = Sum_{d|n} d^2*2^(d-1)*(n/d-1) for n > 0.
%F A077272 G.f.: Sum_{m>0} (m-1)*x^m*(1+2*x^m)/(1-2*x^m)^3. - _Vladeta Jovovic_, Jun 21 2003
%e A077272 a(4) = 1*1*3 + 4*2*1 + 16*8*0 = 11.
%Y A077272 Cf. A083413.
%K A077272 nonn
%O A077272 0,4
%A A077272 _N. J. A. Sloane_, Jun 13 2003