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 A233541 #29 Jan 20 2017 19:57:54
%S A233541 3,6,8,12,12,18,16,23,22,26,24,38,28,34,36,44,36,51,40,56,48,50,48,76,
%T A233541 54,58,62,74,60,88,64,85,72,74,76,112,76,82,84,114,84,116,88,110,108,
%U A233541 98,96,150,102,119,108,128,108,146,116,152,120,122,120,196,124
%N A233541 a(n) = sigma(n) + phi(n) + d(n).
%C A233541 a(n) is the sum of the divisors of n plus the number of positive integers less than or equal to n and relatively prime to n plus the number of divisors of n.
%C A233541 If n is a prime, then a(n) = A064840(n). If n is a prime or a semiprime, then a(n) = 2(d(n) + n - 1).
%H A233541 Indranil Ghosh, <a href="/A233541/b233541.txt">Table of n, a(n) for n = 1..10000</a>
%F A233541 a(n) = A000203(n) + A000010(n) + A000005(n).
%F A233541 Dirichlet g.f.: (zeta(s)^3 + zeta(s-1)*zeta(s)^2 + zeta(s-1))/zeta(s). - _Ilya Gutkovskiy_, Dec 07 2016
%e A233541 a(6) = 18; sigma(6) + phi(6) + d(6) = 12 + 2 + 4 = 18.
%p A233541 with(numtheory); A233541:=n->sigma(n) + phi(n) + tau(n); seq(A233541(n), n=1..100);
%t A233541 Table[DivisorSigma[0,n] + DivisorSigma[1,n] + EulerPhi[n], {n,100}]
%o A233541 (PARI) a(n) = sigma(n) + eulerphi(n) + numdiv(n); \\ _Michel Marcus_, Dec 07 2016
%Y A233541 Cf. A000005, A000010, A000203, A064840.
%K A233541 nonn,easy
%O A233541 1,1
%A A233541 _Wesley Ivan Hurt_, Dec 12 2013