A360219 - cp's OEIS frontend

A360219 a(n) = Sum_{k=0..floor(n/4)} (-1)^k * binomial(n-3k,k) binomial(2(n-3k),n-3*k).

n	a(n)
0	1
1	2
2	6
3	20
4	68
5	240
6	864
7	3152
8	11616
9	43136
10	161152
11	604992
12	2280416
13	8624832
14	32714688
15	124399488
16	474066560
17	1810053120
18	6922776576
19	26517173760
20	101710338048
21	390603984896
22	1501732753408
23	5779500226560
24	22263437981184
25	85835254221824
26	331193445626880

[1, 2, 6, 20, 68, 240, 864, 3152, 11616, 43136, 161152, 604992, 2280416, 8624832, 32714688, 124399488, 474066560, 1810053120, 6922776576, 26517173760, 101710338048, 390603984896, 1501732753408, 5779500226560, 22263437981184, 85835254221824, 331193445626880]

cp's OEIS Frontend

A360219 a(n) = Sum_{k=0..floor(n/4)} (-1)^k * binomial(n-3k,k) binomial(2(n-3k),n-3*k).

Table of values

List of values

cp's OEIS Frontend

A360219 a(n) = Sum_{k=0..floor(n/4)} (-1)^k * binomial(n-3*k,k) * binomial(2*(n-3*k),n-3*k).

Table of values

List of values

A360219 a(n) = Sum_{k=0..floor(n/4)} (-1)^k * binomial(n-3k,k) binomial(2(n-3k),n-3*k).