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%I #13 Sep 18 2022 12:37:01
%S 1,3,9,13,31,43,143,167,185,215,1141,1321,231,763,3277,3517,7289,8009,
%T 24787,26587,27847,29431,332021,355781,365681,382841,394721,413201,
%U 2949827,3157727,643003,665179,3417371,3535181,3616031,3782351,1279777,3956371,4046461
%N Numerator of Sum_{k=1..n} k/phi(k).
%D József Sándor, Dragoslav S. Mitrinovic, and Borislav Crstici, Handbook of Number Theory I, Springer Science & Business Media, 2005, Section I.27, page 29.
%H Amiram Eldar, <a href="/A068885/b068885.txt">Table of n, a(n) for n = 1..1000</a>
%H R. Sitaramachandrarao, <a href="https://www.jstor.org/stable/44236939">On an error term of Landau - II</a>, The Rocky Mountain Journal of Mathematics, Vol. 15, No. 2 (1985), pp. 579-588.
%F a(n)/A069947(n) ~ c * n - log(n)/2 + O(log(n)^(2/3)), where c = zeta(2)*zeta(3)/zeta(6) (A082695) (Sitaramachandrarao, 1985). - _Amiram Eldar_, Sep 18 2022
%e 1, 3, 9/2, 13/2, 31/4, 43/4, 143/12, 167/12, 185/12, ...
%t Numerator @ Accumulate @ Table[k/EulerPhi[k], {k, 1, 40}] (* _Amiram Eldar_, Sep 18 2022 *)
%o (PARI) a(n) = numerator(sum(k=1, n, k/eulerphi(k))); \\ _Michel Marcus_, Sep 18 2022
%Y Cf. A069947 (denominators), A000010, A028415, A048049, A082695.
%K nonn,frac
%O 1,2
%A _N. J. A. Sloane_, Jun 28 2002
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