A303613 - cp's OEIS frontend

A303613 a(n) = [x^n] (1/6 * Sum_{k=0..n} (k+3)!*x^k)^(1/2).

n	a(n)
0	1
1	2
2	8
3	44
4	300
5	2408
6	22056
7	225824
8	2547352
9	31322640
10	416442016
11	5948450912
12	90815006528
13	1475513165184
14	25419300628160
15	462839142264960
16	8882065110092000
17	179190173518717120
18	3791700201187720960
19	83977684252758211200
20	1942984028971973710720

[1, 2, 8, 44, 300, 2408, 22056, 225824, 2547352, 31322640, 416442016, 5948450912, 90815006528, 1475513165184, 25419300628160, 462839142264960, 8882065110092000, 179190173518717120, 3791700201187720960, 83977684252758211200, 1942984028971973710720]

cp's OEIS Frontend

A303613 a(n) = [x^n] (1/6 * Sum_{k=0..n} (k+3)!*x^k)^(1/2).

Table of values

List of values