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

A278052

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

Terms

    a(0) =1a(1) =4a(2) =39a(3) =52a(4) =4069a(5) =8573a(6) =258017a(7) =46639a(8) =53371999a(9) =113518551a(10) =768140741a(11) =1560819091a(12) =242830653007a(13) =169134016817

External references