A047098 - cp's OEIS frontend

A047098 a(n) = 2binomial(3n, n) - Sum_{k=0..n} binomial(3*n, k).

n	a(n)
0	1
1	2
2	8
3	38
4	196
5	1062
6	5948
7	34120
8	199316
9	1181126
10	7080928
11	42860534
12	261542752
13	1607076200
14	9934255472
15	61732449648
16	385393229460
17	2415935640198
18	15200964233864
19	95962904716402
20	607640599286276
21	3858198001960438
22	24559243585545644
23	156692889782067712

[1, 2, 8, 38, 196, 1062, 5948, 34120, 199316, 1181126, 7080928, 42860534, 261542752, 1607076200, 9934255472, 61732449648, 385393229460, 2415935640198, 15200964233864, 95962904716402, 607640599286276, 3858198001960438, 24559243585545644, 156692889782067712]

cp's OEIS Frontend

A047098 a(n) = 2binomial(3n, n) - Sum_{k=0..n} binomial(3*n, k).

Table of values

List of values

cp's OEIS Frontend

A047098 a(n) = 2*binomial(3*n, n) - Sum_{k=0..n} binomial(3*n, k).

Table of values

List of values

A047098 a(n) = 2binomial(3n, n) - Sum_{k=0..n} binomial(3*n, k).