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 A333807 #6 Apr 05 2020 23:28:04
%S A333807 0,1,1,1,1,1,1,1,1,1,1,4,1,1,4,1,1,4,1,1,4,1,1,4,1,1,4,1,1,9,1,1,4,1,
%T A333807 6,4,1,1,4,6,1,4,1,1,9,1,1,4,1,6,4,1,1,4,6,8,4,1,1,9,1,1,11,1,6,4,1,1,
%U A333807 4,13,1,4,1,1,9,1,8,4,1,6,4,1,1,11,6,1,4,1,1,18
%N A333807 Sum of odd divisors of n that are < sqrt(n).
%F A333807 G.f.: Sum_{k>=1} (2*k - 1) * x^(2*k*(2*k - 1)) / (1 - x^(2*k - 1)).
%t A333807 Table[DivisorSum[n, # &, # < Sqrt[n] && OddQ[#] &], {n, 1, 90}]
%t A333807 nmax = 90; CoefficientList[Series[Sum[(2 k - 1) x^(2 k (2 k - 1))/(1 - x^(2 k - 1)), {k, 1, nmax}], {x, 0, nmax}], x] // Rest
%Y A333807 Cf. A000593, A069289, A070039, A333805, A333808, A333810.
%K A333807 nonn
%O A333807 1,12
%A A333807 _Ilya Gutkovskiy_, Apr 05 2020