A374977 - cp's OEIS frontend

A374977 a(n) = Sum_{i+j+k+l=n, i,j,k,l >= 1} sigma(i)sigma(j)sigma(k)*sigma(l).

n	a(n)
1	0
2	0
3	0
4	1
5	12
6	70
7	280
8	885
9	2364
10	5586
11	12000
12	23870
13	44660
14	79272
15	134768
16	220565
17	349440
18	538270
19	807840
20	1187004
21	1706840
22	2415150
23	3354120
24	4601870
25	6209612
26	8303610
27	10935960
28	14309640
29	18460260
30	23708184
31	30044000
32	37967925
33	47368480
34	59022432
35	72633816

[0, 0, 0, 1, 12, 70, 280, 885, 2364, 5586, 12000, 23870, 44660, 79272, 134768, 220565, 349440, 538270, 807840, 1187004, 1706840, 2415150, 3354120, 4601870, 6209612, 8303610, 10935960, 14309640, 18460260, 23708184, 30044000, 37967925, 47368480, 59022432, 72633816]

cp's OEIS Frontend

A374977 a(n) = Sum_{i+j+k+l=n, i,j,k,l >= 1} sigma(i)sigma(j)sigma(k)*sigma(l).

Table of values

List of values

cp's OEIS Frontend

A374977 a(n) = Sum_{i+j+k+l=n, i,j,k,l >= 1} sigma(i)*sigma(j)*sigma(k)*sigma(l).

Table of values

List of values

A374977 a(n) = Sum_{i+j+k+l=n, i,j,k,l >= 1} sigma(i)sigma(j)sigma(k)*sigma(l).