A331080 - cp's OEIS frontend

A331080 a(n) = Sum_{i=1..n} d_3(i)*d_3(i+1), where d_3(n) = A007425(n).

n	a(n)
1	3
2	12
3	30
4	48
5	75
6	102
7	132
8	192
9	246
10	273
11	327
12	381
13	408
14	489
15	624
16	669
17	723
18	777
19	831
20	993
21	1074
22	1101
23	1191
24	1371
25	1425
26	1515
27	1695
28	1749
29	1830
30	1911
31	1974
32	2163
33	2244
34	2325
35	2649
36	2757
37	2784
38	2865
39	3135
40	3225
41	3306
42	3387
43	3441
44	3765
45	3927
46	3954
47	4089
48	4359
49	4467
50	4629
51	4791
52	4845
53	4935
54	5205
55	5475

[3, 12, 30, 48, 75, 102, 132, 192, 246, 273, 327, 381, 408, 489, 624, 669, 723, 777, 831, 993, 1074, 1101, 1191, 1371, 1425, 1515, 1695, 1749, 1830, 1911, 1974, 2163, 2244, 2325, 2649, 2757, 2784, 2865, 3135, 3225, 3306, 3387, 3441, 3765, 3927, 3954, 4089, 4359, 4467, 4629, 4791, 4845, 4935, 5205, 5475]

cp's OEIS Frontend

A331080 a(n) = Sum_{i=1..n} d_3(i)*d_3(i+1), where d_3(n) = A007425(n).

Table of values

List of values