A128045 - cp's OEIS frontend

A128045 a(n) = denominator of b(n), where b(1) = 1, b(n) = Sum_{k=1..n-1} b(n-k) * H(k); H(k) = Sum_{j=1..k} 1/j, the k-th harmonic number.

n	a(n)
1	1
2	1
3	2
4	6
5	2
6	5
7	360
8	2520
9	1680
10	15120
11	2700
12	11880
13	9979200
14	8648640
15	18345600
16	2476656000
17	27243216000
18	714714000
19	427508928000
20	1160381376000
21	1055947052160000
22	22174888095360000
23	38718058579200
24	141031842336000

[1, 1, 2, 6, 2, 5, 360, 2520, 1680, 15120, 2700, 11880, 9979200, 8648640, 18345600, 2476656000, 27243216000, 714714000, 427508928000, 1160381376000, 1055947052160000, 22174888095360000, 38718058579200, 141031842336000]

cp's OEIS Frontend

A128045 a(n) = denominator of b(n), where b(1) = 1, b(n) = Sum_{k=1..n-1} b(n-k) * H(k); H(k) = Sum_{j=1..k} 1/j, the k-th harmonic number.

Table of values

List of values