A000245 - cp's OEIS frontend

A000245 a(n) = 3(2n)!/((n+2)!*(n-1)!).

n	a(n)
0	0
1	1
2	3
3	9
4	28
5	90
6	297
7	1001
8	3432
9	11934
10	41990
11	149226
12	534888
13	1931540
14	7020405
15	25662825
16	94287120
17	347993910
18	1289624490
19	4796857230
20	17902146600
21	67016296620
22	251577050010
23	946844533674
24	3572042254128
25	13505406670700
26	51166197843852
27	194214400834356

[0, 1, 3, 9, 28, 90, 297, 1001, 3432, 11934, 41990, 149226, 534888, 1931540, 7020405, 25662825, 94287120, 347993910, 1289624490, 4796857230, 17902146600, 67016296620, 251577050010, 946844533674, 3572042254128, 13505406670700, 51166197843852, 194214400834356]

cp's OEIS Frontend

A000245 a(n) = 3(2n)!/((n+2)!*(n-1)!).

Table of values

List of values

cp's OEIS Frontend

A000245 a(n) = 3*(2*n)!/((n+2)!*(n-1)!).

Table of values

List of values

A000245 a(n) = 3(2n)!/((n+2)!*(n-1)!).