A372963 - cp's OEIS frontend

A372963 a(n) = Sum_{1 <= x_1, x_2, x_3, x_4 <= n} ( n/gcd(x_1, x_2, x_3, x_4, n) )^2.

n	a(n)
1	1
2	61
3	721
4	3901
5	15601
6	43981
7	117601
8	249661
9	525601
10	951661
11	1771441
12	2812621
13	4826641
14	7173661
15	11248321
16	15978301
17	24137281
18	32061661
19	47045521
20	60859501
21	84790321
22	108057901
23	148035361
24	180005581
25	243765601
26	294425101
27	383163121
28	458761501
29	594822481
30	686147581

[1, 61, 721, 3901, 15601, 43981, 117601, 249661, 525601, 951661, 1771441, 2812621, 4826641, 7173661, 11248321, 15978301, 24137281, 32061661, 47045521, 60859501, 84790321, 108057901, 148035361, 180005581, 243765601, 294425101, 383163121, 458761501, 594822481, 686147581]

cp's OEIS Frontend

A372963 a(n) = Sum_{1 <= x_1, x_2, x_3, x_4 <= n} ( n/gcd(x_1, x_2, x_3, x_4, n) )^2.

Table of values

List of values