A133443 - cp's OEIS frontend

A133443 a(n) = Sum_{k=0..n} C(n,floor(k/2))(-1)^k3^(n-k).

n	a(n)
0	1
1	2
2	8
3	24
4	84
5	272
6	920
7	3040
8	10180
9	33840
10	112968
11	376224
12	1254696
13	4181088
14	13939248
15	46459584
16	154873860
17	516229040
18	1720795880
19	5735921440
20	19119861304
21	63732624672
22	212442552528
23	708140901184
24	2360471473384
25	7868234639072
26	26227455730640

[1, 2, 8, 24, 84, 272, 920, 3040, 10180, 33840, 112968, 376224, 1254696, 4181088, 13939248, 46459584, 154873860, 516229040, 1720795880, 5735921440, 19119861304, 63732624672, 212442552528, 708140901184, 2360471473384, 7868234639072, 26227455730640]

cp's OEIS Frontend

A133443 a(n) = Sum_{k=0..n} C(n,floor(k/2))(-1)^k3^(n-k).

Table of values

List of values

cp's OEIS Frontend

A133443 a(n) = Sum_{k=0..n} C(n,floor(k/2))*(-1)^k*3^(n-k).

Table of values

List of values

A133443 a(n) = Sum_{k=0..n} C(n,floor(k/2))(-1)^k3^(n-k).