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 A193349 #19 Aug 12 2024 04:23:31
%S A193349 1,1,1,4,1,1,1,1,4,1,1,4,1,1,1,6,1,4,1,4,1,1,1,1,4,1,1,4,1,1,1,4,1,1,
%T A193349 1,13,1,1,1,1,1,1,1,4,4,1,1,6,4,4,1,4,1,1,1,1,1,1,1,4,1,1,4,8,1,1,1,4,
%U A193349 1,1,1,4,1,1,4,4,1,1,1,6,6,1,1,4,1,1
%N A193349 Sum of odd divisors of tau(n).
%H A193349 Reinhard Zumkeller, <a href="/A193349/b193349.txt">Table of n, a(n) for n = 1..10000</a>
%F A193349 a(n) = A000593(A000005(n)). - _Reinhard Zumkeller_, Jul 25 2011
%F A193349 From _Amiram Eldar_, Aug 12 2024: (Start)
%F A193349 a(n) = 1 if and only if n is in A036537.
%F A193349 a(n) = A062069(n) if and only if n is a square. (End)
%e A193349 a(36) = 13 because tau(36) = 9 and the sum of the 3 odd divisors {1, 3, 9} is 13.
%t A193349 Table[Total[Select[Divisors[DivisorSigma[0,n]], OddQ[ # ]&]], {n, 80}]
%o A193349 (PARI) a(n)=sumdiv(sigma(n,0),d,(d%2)*d);
%Y A193349 Cf. A000005, A000593, A036537, A062069, A193348.
%K A193349 nonn
%O A193349 1,4
%A A193349 _Michel Lagneau_, Jul 23 2011