A193446 - cp's OEIS frontend

A193446 a(n) = n! * Sum_{k=1..n-1} H(k)*H(n-k) for n>=2, where H(n) is the n-th harmonic number.

n	a(n)
2	2
3	18
4	142
5	1160
6	10208
7	97720
8	1018008
9	11507472
10	140581872
11	1848236544
12	26041957632
13	391738883328
14	6268657962240
15	106361504663040
16	1907768564282880
17	36075270482058240
18	717379367864693760
19	14967427450111488000
20	326956068509511168000
21	7463341244426167296000

[2, 18, 142, 1160, 10208, 97720, 1018008, 11507472, 140581872, 1848236544, 26041957632, 391738883328, 6268657962240, 106361504663040, 1907768564282880, 36075270482058240, 717379367864693760, 14967427450111488000, 326956068509511168000, 7463341244426167296000]

cp's OEIS Frontend

A193446 a(n) = n! * Sum_{k=1..n-1} H(k)*H(n-k) for n>=2, where H(n) is the n-th harmonic number.

Table of values

List of values