A085831 - cp's OEIS frontend

A085831 a(n) = Sum_{k=1..2^n} d(k) where d(n) = number of divisors of n (A000005).

n	a(n)
0	1
1	3
2	8
3	20
4	50
5	119
6	280
7	645
8	1466
9	3280
10	7262
11	15937
12	34720
13	75108
14	161552
15	345785
16	736974
17	1564762
18	3311206
19	6985780
20	14698342
21	30850276
22	64607782
23	135030018
24	281689074
25	586636098
26	1219788256
27	2532608855
28	5251282902
29	10874696106
30	22493653324
31	46475828418

[1, 3, 8, 20, 50, 119, 280, 645, 1466, 3280, 7262, 15937, 34720, 75108, 161552, 345785, 736974, 1564762, 3311206, 6985780, 14698342, 30850276, 64607782, 135030018, 281689074, 586636098, 1219788256, 2532608855, 5251282902, 10874696106, 22493653324, 46475828418]

cp's OEIS Frontend

A085831 a(n) = Sum_{k=1..2^n} d(k) where d(n) = number of divisors of n (A000005).

Table of values

List of values