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 A292768 #12 Dec 03 2023 05:01:33 %S A292768 2,6,12,21,31,45,59,78,97,119,141,173,199,229,261,300,334,379,417,467, %T A292768 511,557,603,671,722,776,834,902,960,1040,1102,1181,1249,1319,1391, %U A292768 1494,1568,1646,1726,1832,1914,2022,2108,2212,2314,2408,2502,2642,2741,2854,2958,3080,3186,3324,3436 %N A292768 Partial sums of A065387. %H A292768 N. J. A. Sloane, <a href="/A292768/b292768.txt">Table of n, a(n) for n = 1..10000</a> %F A292768 G.f.: (1/(1 - x))*Sum_{k>=1} (mu(k) + 1)*x^k/(1 - x^k)^2. - _Ilya Gutkovskiy_, Sep 28 2017 %F A292768 a(n) = (3/(Pi^2) + Pi^2/12) * n^2 + O(n*log(n)). - _Amiram Eldar_, Dec 03 2023 %t A292768 Accumulate @ Table[EulerPhi[n] + DivisorSigma[1, n], {n, 100}] (* _Amiram Eldar_, Dec 03 2023 *) %o A292768 (PARI) lista(nmax) = {my(f, s = 0); for(n = 1, nmax, f = factor(n); s += (sigma(f) + eulerphi(f)); print1(s, ", "));} \\ _Amiram Eldar_, Dec 03 2023 %Y A292768 Cf. A000010, A000203, A065387. %K A292768 nonn %O A292768 1,1 %A A292768 _N. J. A. Sloane_, Sep 28 2017