A371870 - cp's OEIS frontend

A371870 a(n) = Sum_{k=0..floor(n/2)} binomial(2n-k-1,n-2k).

n	a(n)
0	1
1	1
2	4
3	14
4	51
5	189
6	709
7	2683
8	10220
9	39130
10	150438
11	580328
12	2245004
13	8705686
14	33828704
15	131688362
16	513445147
17	2004688605
18	7836832057
19	30670416703
20	120153739079
21	471143251989
22	1848978071615
23	7261781367389
24	28540427527441
25	112243216215879
26	441693646453729

[1, 1, 4, 14, 51, 189, 709, 2683, 10220, 39130, 150438, 580328, 2245004, 8705686, 33828704, 131688362, 513445147, 2004688605, 7836832057, 30670416703, 120153739079, 471143251989, 1848978071615, 7261781367389, 28540427527441, 112243216215879, 441693646453729]

cp's OEIS Frontend

A371870 a(n) = Sum_{k=0..floor(n/2)} binomial(2n-k-1,n-2k).

Table of values

List of values

cp's OEIS Frontend

A371870 a(n) = Sum_{k=0..floor(n/2)} binomial(2*n-k-1,n-2*k).

Table of values

List of values

A371870 a(n) = Sum_{k=0..floor(n/2)} binomial(2n-k-1,n-2k).