Let v = list of denominators of Farey series of order n (see A006843); a(n) = sum of products of adjacent terms of v.

A278046

Let v = list of denominators of Farey series of order n (see A006843); a(n) = sum of products of adjacent terms of v.

Terms

    a(0) =1a(1) =4a(2) =18a(3) =44a(4) =124a(5) =186a(6) =424a(7) =636a(8) =1038a(9) =1378a(10) =2368a(11) =2852a(12) =4516a(13) =5510a(14) =7030a(15) =8734a(16) =12542a(17) =14168a(18) =19526a(19) =22206a(20) =26658a(21) =30728a(22) =40342a(23) =44190a(24) =54590a(25) =61402a(26) =72328a(27) =80196a(28) =99684a(29) =105644

External references