A278052 - cp's OEIS frontend

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).

n	a(n)
1	1
2	4
3	39
4	52
5	4069
6	8573
7	258017
8	46639
9	53371999
10	113518551
11	768140741
12	1560819091
13	242830653007
14	169134016817
15	38186305937387
16	408881289764107
17	143220706672837
18	41293923006131
19	9928250098118791
20	10936700271572951
21	97615258031147892517
22	643700119549549507
23	62211198375587838727

[1, 4, 39, 52, 4069, 8573, 258017, 46639, 53371999, 113518551, 768140741, 1560819091, 242830653007, 169134016817, 38186305937387, 408881289764107, 143220706672837, 41293923006131, 9928250098118791, 10936700271572951, 97615258031147892517, 643700119549549507, 62211198375587838727]

cp's OEIS Frontend

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).

Table of values

List of values