A387602 - cp's OEIS frontend

A387602 a(n) = (1/2) * Sum_{k=0..floor(n/3)} 2^(n-2k) binomial(2n-4k+2,2*k+1).

n	a(n)
0	1
1	4
2	12
3	36
4	120
5	416
6	1420
7	4768
8	15968
9	53664
10	180736
11	608640
12	2048336
13	6891968
14	23191104
15	78044352
16	262644608
17	883866624
18	2974400960
19	10009502720
20	33684265984
21	113355412480
22	381467226112
23	1283724873728
24	4320028764416
25	14537889756160
26	48923344206848

[1, 4, 12, 36, 120, 416, 1420, 4768, 15968, 53664, 180736, 608640, 2048336, 6891968, 23191104, 78044352, 262644608, 883866624, 2974400960, 10009502720, 33684265984, 113355412480, 381467226112, 1283724873728, 4320028764416, 14537889756160, 48923344206848]

cp's OEIS Frontend

A387602 a(n) = (1/2) * Sum_{k=0..floor(n/3)} 2^(n-2k) binomial(2n-4k+2,2*k+1).

Table of values

List of values

cp's OEIS Frontend

A387602 a(n) = (1/2) * Sum_{k=0..floor(n/3)} 2^(n-2*k) * binomial(2*n-4*k+2,2*k+1).

Table of values

List of values

A387602 a(n) = (1/2) * Sum_{k=0..floor(n/3)} 2^(n-2k) binomial(2n-4k+2,2*k+1).