A278561 - cp's OEIS frontend

A278561 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) = denominator of b(n).

n	a(n)
1	2
2	3
3	10
4	7
5	252
6	396
7	6435
8	858
9	680680
10	1175720
11	5290740
12	9360540
13	1029659400
14	617795640
15	116454478140
16	1061790830100
17	283144221360
18	74511637200
19	14060345939640
20	14060345939640
21	109530094869795600
22	650075097225840
23	51193413906534900
24	481218090721428060

[2, 3, 10, 7, 252, 396, 6435, 858, 680680, 1175720, 5290740, 9360540, 1029659400, 617795640, 116454478140, 1061790830100, 283144221360, 74511637200, 14060345939640, 14060345939640, 109530094869795600, 650075097225840, 51193413906534900, 481218090721428060]

cp's OEIS Frontend

A278561 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) = denominator of b(n).

Table of values

List of values