A383581 - cp's OEIS frontend

A383581 a(n) = Sum_{k=0..floor(n/3)} binomial(n-2k,k) binomial(2(n-3k),n-3*k).

n	a(n)
0	1
1	2
2	6
3	21
4	74
5	270
6	1005
7	3788
8	14418
9	55289
10	213270
11	826614
12	3216629
13	12558928
14	49175136
15	193023965
16	759299438
17	2992534344
18	11813985377
19	46709675040
20	184928644350
21	733047010709
22	2908981549006
23	11555513379450
24	45945148281437
25	182835149061920
26	728149606630164

[1, 2, 6, 21, 74, 270, 1005, 3788, 14418, 55289, 213270, 826614, 3216629, 12558928, 49175136, 193023965, 759299438, 2992534344, 11813985377, 46709675040, 184928644350, 733047010709, 2908981549006, 11555513379450, 45945148281437, 182835149061920, 728149606630164]

cp's OEIS Frontend

A383581 a(n) = Sum_{k=0..floor(n/3)} binomial(n-2k,k) binomial(2(n-3k),n-3*k).

Table of values

List of values

cp's OEIS Frontend

A383581 a(n) = Sum_{k=0..floor(n/3)} binomial(n-2*k,k) * binomial(2*(n-3*k),n-3*k).

Table of values

List of values

A383581 a(n) = Sum_{k=0..floor(n/3)} binomial(n-2k,k) binomial(2(n-3k),n-3*k).