Let v = list of denominators of Farey series of order n (see A006843); let b(n) = Sum 1/(k+k'), where (k,k') are pairs of successive terms of v; a(n) = numerator of b(n).

A278050

Let v = list of denominators of Farey series of order n (see A006843); let b(n) = Sum 1/(k+k'), where (k,k') are pairs of successive terms of v; a(n) = numerator of b(n).

Terms

    a(0) =1a(1) =2a(2) =9a(3) =38a(4) =347a(5) =4189a(6) =11767a(7) =1733a(8) =1548081a(9) =31464371a(10) =14680543a(11) =353517989a(12) =3350216417a(13) =10571768267a(16) =538250871701a(17) =110983833313

External references