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 A193433 #32 Apr 17 2025 14:55:33
%S A193433 1,3,6,18,18,42,38,93,84,126,102,186,180,324,198,342,258,540,434,546,
%T A193433 402,756,588,972,578,942,678,1332,948,1266,972,1596,1302,1980,1260,
%U A193433 1842,1298,2484,1842,2286,1602,2613,2124,3534,2100,3042,2220,4536,2772,3606
%N A193433 Sum of the divisors of n^2+1.
%H A193433 Amiram Eldar, <a href="/A193433/b193433.txt">Table of n, a(n) for n = 0..10000</a>
%F A193433 a(n) = A000203(A002522(n)). - _Michel Marcus_, Mar 16 2018
%e A193433 a(7) = 93 because 7^2+1 = 50 and the sum of the 6 divisors { 1, 2, 5, 10, 25, 50} is 93.
%p A193433 with(numtheory):for n from 0 to 110 do:x:=divisors(n^2+1):n1:=nops(x):s:=0:for m from 1 to n1 do: s:=s+x[m]:od: printf(`%d, `, s):od:
%t A193433 Table[Total[Divisors[n^2 + 1]], {n, 0, 100}] (* _T. D. Noe_, Jul 28 2011 *)
%t A193433 DivisorSigma[1,Range[0,50]^2+1] (* _Harvey P. Dale_, Aug 03 2020 *)
%o A193433 (PARI) a(n) = sigma(n^2+1); \\ _Michel Marcus_, Mar 17 2018
%o A193433 (Python)
%o A193433 from sympy import divisor_sigma
%o A193433 def A193433(n): return divisor_sigma(n**2+1) # _Chai Wah Wu_, Apr 17 2025
%Y A193433 Cf. A000203, A002522, A193432.
%K A193433 nonn
%O A193433 0,2
%A A193433 _Michel Lagneau_, Jul 28 2011