A000917 - cp's OEIS frontend

A000917 a(n) = (2n+3)!/(n!*(n+2)!).

n	a(n)
0	3
1	20
2	105
3	504
4	2310
5	10296
6	45045
7	194480
8	831402
9	3527160
10	14872858
11	62403600
12	260757900
13	1085822640
14	4508102925
15	18668849760
16	77138650050
17	318107374200
18	1309542023790
19	5382578744400
20	22093039119060
21	90567738003600
22	370847442355650
23	1516927277253024

[3, 20, 105, 504, 2310, 10296, 45045, 194480, 831402, 3527160, 14872858, 62403600, 260757900, 1085822640, 4508102925, 18668849760, 77138650050, 318107374200, 1309542023790, 5382578744400, 22093039119060, 90567738003600, 370847442355650, 1516927277253024]

cp's OEIS Frontend

A000917 a(n) = (2n+3)!/(n!*(n+2)!).

Table of values

List of values