A099780 - cp's OEIS frontend

A099780 a(n) = Sum_{k=0..floor(n/3)} C(n-k, 2k) 2^k3^(n-3k).

n	a(n)
0	1
1	3
2	9
3	29
4	99
5	351
6	1273
7	4677
8	17307
9	64295
10	239361
11	892125
12	3327091
13	12412143
14	46313289
15	172824629
16	644952459
17	2406919671
18	8982595153
19	33523198797
20	125109675747
21	466914455615
22	1742546049561
23	6503265548325
24	24270507755131
25	90578748694983
26	338044453470369

[1, 3, 9, 29, 99, 351, 1273, 4677, 17307, 64295, 239361, 892125, 3327091, 12412143, 46313289, 172824629, 644952459, 2406919671, 8982595153, 33523198797, 125109675747, 466914455615, 1742546049561, 6503265548325, 24270507755131, 90578748694983, 338044453470369]

cp's OEIS Frontend

A099780 a(n) = Sum_{k=0..floor(n/3)} C(n-k, 2k) 2^k3^(n-3k).

Table of values

List of values

cp's OEIS Frontend

A099780 a(n) = Sum_{k=0..floor(n/3)} C(n-k, 2*k) * 2^k*3^(n-3*k).

Table of values

List of values

A099780 a(n) = Sum_{k=0..floor(n/3)} C(n-k, 2k) 2^k3^(n-3k).