A364211 - cp's OEIS frontend

A364211 a(n) = (1/(4n)) Sum_{d|n} 5^(n/d-1) * phi(5*d).

n	a(n)
1	1
2	3
3	9
4	33
5	126
6	527
7	2233
8	9783
9	43409
10	195378
11	887785
12	4069297
13	18780049
14	87194199
15	406901134
16	1907353533
17	8975758273
18	42385547227
19	200773540297
20	953674414158
21	4541306270097
22	21674416725855
23	103660251783289
24	496705375169547
25	2384185791015751
26	11462431696965147
27	55189485903168409

[1, 3, 9, 33, 126, 527, 2233, 9783, 43409, 195378, 887785, 4069297, 18780049, 87194199, 406901134, 1907353533, 8975758273, 42385547227, 200773540297, 953674414158, 4541306270097, 21674416725855, 103660251783289, 496705375169547, 2384185791015751, 11462431696965147, 55189485903168409]

cp's OEIS Frontend

A364211 a(n) = (1/(4n)) Sum_{d|n} 5^(n/d-1) * phi(5*d).

Table of values

List of values

cp's OEIS Frontend

A364211 a(n) = (1/(4*n)) * Sum_{d|n} 5^(n/d-1) * phi(5*d).

Table of values

List of values

A364211 a(n) = (1/(4n)) Sum_{d|n} 5^(n/d-1) * phi(5*d).