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Numerators of row sums of array of ratios A111879(n,k)/A111880(n,k).
2

%I #5 Oct 12 2012 14:40:23

%S 1,1,29,1,103,253,1669,181,30791,849,452993,41003,94949,421117,

%T 18358463,446801,124184839,30064511,80932487,19812817,211524139,

%U 333707681,4757207109,2557825027,105920383973,14417396537,4649180818987

%N Numerators of row sums of array of ratios A111879(n,k)/A111880(n,k).

%C The denominators are given in A069220(n), n>=3.

%F a(n)= numerator(sum(r(n, k), k=1..phi(n)-1), with phi(n):=A000010(n) (Euler's totient function) and the ratios r(n, k):=A111879(n, k)/A111880(n, k).

%e The ratios a(n)/A069220(n) are: 1/2, 1/3, 29/12, 1/5, 103/20, 253/105, 1669/280, 181/63, 30791/2520, 849/385, ... (see the W. Lang link under A111879.)

%K nonn,easy,frac

%O 3,3

%A _Wolfdieter Lang_, Aug 23 2005