A371003 - cp's OEIS frontend

A371003 a(n) = binomial(2n-1,n) - binomial(n,2)(binomial(n-1,2) + 2) - 1.

n	a(n)
1	0
2	0
3	0
4	4
5	45
6	281
7	1358
8	5790
9	23229
10	90667
11	350130
12	1348315
13	5194995
14	20051019
15	77548994
16	300527354
17	1166786517
18	4537546535
19	17672605394
20	68923231539
21	269128896899
22	1052049432887
23	4116715304850
24	16123801771169
25	63205303135475
26	247959266375901
27	973469712709278

[0, 0, 0, 4, 45, 281, 1358, 5790, 23229, 90667, 350130, 1348315, 5194995, 20051019, 77548994, 300527354, 1166786517, 4537546535, 17672605394, 68923231539, 269128896899, 1052049432887, 4116715304850, 16123801771169, 63205303135475, 247959266375901, 973469712709278]

cp's OEIS Frontend

A371003 a(n) = binomial(2n-1,n) - binomial(n,2)(binomial(n-1,2) + 2) - 1.

Table of values

List of values

cp's OEIS Frontend

A371003 a(n) = binomial(2*n-1,n) - binomial(n,2)*(binomial(n-1,2) + 2) - 1.

Table of values

List of values

A371003 a(n) = binomial(2n-1,n) - binomial(n,2)(binomial(n-1,2) + 2) - 1.