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 A063514 #33 Dec 25 2024 04:23:54
%S A063514 0,0,0,1,2,0,2,3,1,2,2,0,2,0,0,7,2,3,2,2,8,6,2,4,11,6,4,8,2,0,2,15,8,
%T A063514 6,0,7,2,6,8,10,2,0,2,4,6,6,2,12,15,13,8,2,2,12,32,0,8,6,2,8,2,6,32,
%U A063514 31,36,4,2,30,8,0,2,3,2,6,4,32,36,0,2,26,13,6,2
%N A063514 a(n) = sigma(n) mod phi(n).
%C A063514 If a(n) = 0, then n is a balanced number (A020492).
%H A063514 Harry J. Smith, <a href="/A063514/b063514.txt">Table of n, a(n) for n = 1..2000</a>
%F A063514 a(p^2) = 2*p+1, for prime p >= 5. - _Michel Marcus_, Apr 07 2020
%t A063514 a[n_] := Mod[DivisorSigma[1, n], EulerPhi[n]]; Array[a, 100] (* _Amiram Eldar_, Dec 25 2024 *)
%o A063514 (PARI) a(n) = { sigma(n)%eulerphi(n) } \\ _Harry J. Smith_, Aug 24 2009
%o A063514 (Magma) [SumOfDivisors(n) mod EulerPhi(n): n in [1..85]]; // _Bruno Berselli_, Jan 31 2013
%Y A063514 Cf. A000010, A000203, A020492, A023897.
%K A063514 nonn,easy
%O A063514 1,5
%A A063514 _Labos Elemer_, Jul 31 2001