A270715 - cp's OEIS frontend

A270715 a(n) = ((n+2)/2)Sum_{k=0..n/2}(Sum_{i=0..n-2k} binomial(k+1,n-2k-i)binomial(k+i,k))/(k+1).

n	a(n)
0	1
1	3
2	5
3	10
4	19
5	35
6	65
7	120
8	221
9	407
10	749
11	1378
12	2535
13	4663
14	8577
15	15776
16	29017
17	53371
18	98165
19	180554
20	332091
21	610811
22	1123457
23	2066360
24	3800629
25	6990447
26	12857437
27	23648514
28	43496399
29	80002351
30	147147265

[1, 3, 5, 10, 19, 35, 65, 120, 221, 407, 749, 1378, 2535, 4663, 8577, 15776, 29017, 53371, 98165, 180554, 332091, 610811, 1123457, 2066360, 3800629, 6990447, 12857437, 23648514, 43496399, 80002351, 147147265]

cp's OEIS Frontend

A270715 a(n) = ((n+2)/2)Sum_{k=0..n/2}(Sum_{i=0..n-2k} binomial(k+1,n-2k-i)binomial(k+i,k))/(k+1).

Table of values

List of values

cp's OEIS Frontend

A270715 a(n) = ((n+2)/2)*Sum_{k=0..n/2}(Sum_{i=0..n-2*k} binomial(k+1,n-2*k-i)*binomial(k+i,k))/(k+1).

Table of values

List of values

A270715 a(n) = ((n+2)/2)Sum_{k=0..n/2}(Sum_{i=0..n-2k} binomial(k+1,n-2k-i)binomial(k+i,k))/(k+1).